JPH03219064A - Electronic equipment parts - Google Patents

Abstract

PURPOSE:To improve heat resisting reliability by plating the surface of a phosphor bronze substrate with Ni to specific thickness, allowing Ni to diffuse into the substrate, and then providing a metallic layer on the above. CONSTITUTION:The surface of a phosphor bronze substrate is plated with Ni to >=0.01mum thickness, and Ni is allowed to diffuse into the phosphor bronze substrate by means of annealing, etc., to carry out alloying. Subsequently, metal plating with Sn, Sn alloy, etc., is applied to the resulting Ni diffused layer, by which electronic equipment parts can be formed. By this method, the heat resisting reliability of the metallic layer of Sn plating, etc., can be improved, and effective application to electronic equipment parts used at high temp., such as automobile parts, can be attained.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to parts for electronic devices, which are used in electrical and electronic devices, and which have a copper alloy substrate on which a metal layer such as tin and tin alloy plating is formed on the surface. It is related to.

(Prior art) Various plated steel alloys such as gold or tin alloys, which have good conductivity and solderability, have been used as electronic device parts for a long time, but as electric and electronic device parts become denser and quality increases, There is a need for materials with excellent reliability as contacts.

Furthermore, due to the demand for lower costs that has become stronger in recent years,
There is a need for materials for electrical and electronic equipment that are reliable, reliable, and low cost. For this reason, galvanized steel alloys are required to have higher reliability and lower cost than ever before.

Currently, plated steel alloys are used as parts for electronic equipment to meet these demands, especially bronze (Sn3-10.Po).
, 01-0.5 and the balance steel Gaiden-I%)
In particular, in recent years, Fe, Cr, Zr, Co, and Z have been added to phosphor bronze for the purpose of improving various properties.
n.

Phosphor bronze to which trace amounts of Si, Mn, etc. are added has also been widely used.

To give an example of how these steel alloys are used as contact metals, gold plating is the mainstream in industrial connectors, etc., but due to the demand for lower costs in consumer connectors, gold plating is used instead of expensive gold plating. Cheap tin plating is used.

Although tin plating is less reliable than gold plating, stable contact can be obtained by increasing the contact pressure. In order to improve the reliability of tin plating, as disclosed in, for example, Japanese Unexamined Patent Publication No. 1-134957, zinc is diffused and coated on the surface of a copper alloy to improve solderability.

[Problem to be solved by the invention]

However, in order to meet the increasingly strict demands for high reliability and low cost for electric and electronic equipment parts, there have been problems that conventional copper alloys cannot meet.

In recent years, heat resistance reliability has become increasingly important as an item for reliability evaluation of parts for electronic devices such as connectors, assuming that they will be used under high temperatures such as in automobiles.

Currently, one of the evaluation standards for heat resistance reliability is to evaluate the adhesion of plating after being held at 100°C for 1000 hours. In order to satisfy the standards, (1) Copper F base plating with a thickness of 2 μm or less, or (2) Nickel base plating with a J'J thickness of 0.5 μm or less]-
It is necessary to apply However, each of the above methods has its own problems; applying a thick copper base plating increases the plating process time and costs, and nickel base plating has a hard plating film compared to the material, so it is difficult to press. The wear of the mold during machining will increase, and the life of the casting edge will be shortened.

In order to solve the problems of copper alloys with tin and tin alloy plating as contact metals in electronic equipment parts such as electronic equipment parts, the present invention has developed a method of applying 0.01 μm of nickel to the surface of a copper alloy substrate.
The object of the present invention is to provide low-cost parts for electronic devices with high reliability of tin plating by plating the nickel on the tin material and further diffusing the nickel into the material.

(Means for Solving the Problems) This invention provides a method for forming a phosphor bronze substrate with a thickness of 0.01 μm or more on the surface.
The present invention relates to an electronic device component characterized by having a nickel diffusion layer plated with nickel and diffusing the nickel into a phosphor bronze substrate, and a metal layer formed on the nickel diffusion layer.

(Function) Since nickel is diffused into the phosphor bronze substrate and alloyed, the heat resistance reliability of tin plating is improved, and the reason for this is explained below.

It is known that when nickel is used as a base plating for metal layers such as tin and tin alloys, it has the effect of preventing elements from diffusing from the copper alloy base material into tin and tin alloys. Even without forming a single layer like base plating, if it is contained in a copper alloy at a certain concentration, it has the effect of suppressing the diffusion of additive elements in the copper alloy.

P in phosphor bronze is a factor that inhibits the heat resistance reliability of phosphor bronze with tin and tin alloy plating.

This is because trace amounts of added elements such as Fe and Si diffuse into the plating layer and segregate at the interface between the base material and the plating layer, or form brittle compounds, causing peeling between the lubricant and the plating layer.

By plating nickel on the surface of the Il material and further diffusing this nickel into the JJ sealing material, a nickel-containing layer is formed in several microns on the surface of the Fu material, and the P, Fe, and Si in the Il material are This layer suppresses the diffusion of such substances, prevents segregation and the formation of brittle compounds at the interface between the base material and the plating film, and prevents the base material and the plating layer from peeling off. If the nickel plating layer is too thick, it will take time to diffuse the entire plating layer, and if it is too thin, there will be no suppressing effect.
A thickness of 0f-1.0 μm is suitable.

In addition, the nickel-containing layer on the surface of the t-metal material is softer than the nickel plating layer and has a hardness comparable to that of the base material, thereby reducing wear on the mold during press working and extending its life.

Ni, Fe, Cr, Zr, Co on phosphor bronze.

0.05 to 0.8fi of one or more of Zn, Si, and Mn
By adding i%, various properties such as mechanical properties and plating properties of phosphor bronze are improved, so in many cases, the above-mentioned characteristic elements are added.

Phosphor bronze boards are used with a metal layer such as tin or tin alloy plating formed on the surface to improve solderability.
The properties of the plating layer can be improved by subjecting the tin and tin alloy plating layer to reflow treatment.

〔Example〕

The present invention will be explained below based on examples.

The electronic R equipment component according to the present invention has Sn0.5 to 10, P
o, a phosphor bronze substrate consisting of a composition of each weight% of 01 to 0.5 and the balance steel /, ff a copper substrate with Ni, Fe,
Cr, Zr, Co, Zn.

Nickel plating is applied to the final annealing of a special phosphor bronze substrate containing 0.05 to 0.8% by weight of one or more of Si and Mn, and the final annealing of the base material and diffusion of the nickel plating are performed at 500°C. After heat treatment for 5 hours, finish rolling was performed, and the final tin and tin alloy plating was applied.

For comparison, conventional tin-plated phosphorus and +1 copper were also tested, and a heat resistance reliability test was conducted.

Tests were conducted under the following test conditions on electronic device parts based on examples of the present invention and conventional comparative parts in which special additive components and plating thickness were varied.

(1) Heat resistance temperature: 100°C (2) Heat resistance time 7500 hours and 1000 hours (3) Peel test = 180° close bending Table 1 shows electronic device parts according to the present invention and comparison part 11'1
This is a table in which heat resistance reliability was measured, and Examples 2 to 13 are parts for electronic devices according to the present invention.

Example 2 is a part in which a phosphorous copper substrate was plated with 0.01 μm of nickel and then heat treated, and there was no peeling of the plating layer even after a 1000 hour heat resistance test.

Example 3 contains ZrO, 15.1jjt%, and Example 5 contains Cr.
0916% by weight, Example 6 is Ni0.2% by weight, Example 7 is Fed, 5% by weight, Example 8 is SiO,2+'1
lrJ%, Example 9 is MnO, 3 and C.

In Example 12, 0.25% by weight of Zn was added, respectively, and the plated layer did not peel off even after the 1000-hour heat resistance test. In Examples 5 and 11, the parts were not plated with a base plate, but the plated layer did not peel off even after the 1000-hour heat resistance test. Example 4 is a part heat-treated after plating with 0.5 μm nickel, Example 10 is a part soldered with 2.0 μm tin alloy, and Example 13 is a part soldered with 2.0 μm tin alloy.
These parts were soldered and then reflow-treated, and there was no peeling of the plating layer in any of the parts even after the 1000-hour heat resistance test.

In all Examples, no peeling occurred between the R) material and the plating layer even after the 1000 hour heat resistance test. However, the conventional comparative parts with a copper undercoating of 2 μm (Comparative Example 14) and a nickel undercoating of 0.5 μm (Comparative Example 18) did not peel off even after the heat resistance test for too many hours. All comparative parts whose base plating thickness is less than the above are 100
Peeling occurred after the 0 hour heat resistance test. In addition, even on parts that were heat-treated after nickel plating, when the nickel plating thickness was as thin as 0.005 μm (Comparative Example 1), peeling occurred after the 1000-hour heat resistance test, so in order to obtain the effect of suppressing the nickel diffusion layer, Nickel plating thickness is 0.01μ
m or more is required.

(Effects of the Invention) The parts for electronic devices according to the present invention are made by plating nickel on the surface of a phosphor bronze substrate and further diffusing this nickel into the base material to form a nickel diffusion layer. The heat resistance and reliability of the layer are improved, making it extremely effective for use in electronic device parts used at high temperatures, such as automobile parts.

Claims (1)

[Claims] It is characterized by having a nickel diffusion layer in which the surface of a phosphor bronze substrate is plated with nickel with a thickness of 0.01 μm or more and the nickel is diffused into the phosphor bronze substrate, and a metal layer formed on the nickel diffusion layer. Parts for electronic equipment.