Connectors

Basic Knowledge of Plating

# Trivia

Plating plays an important role in the function and performance of connectors. It is also used in various forms in our daily life.

The purpose, types, and materials of plating, which may seem familiar but are not well understood in detail, are introduced here.

What is Plating?

Plating is a general term for the technology of forming a metal film on the solid surface of metals and non-metals. In particular, the method of dissolving a metal in a solution and electrochemically extracting it onto the material surface is generally called "Plating".
Plating Type

The contact parts of the connector are also plated.

For more information about contacts (terminals), click here.

Everyday items that use plating

Smartphones, PCs and other electronic devices: Printed wiring (copper plating), LSI packages (gold, nickel, solder plating), chip components (tin plating), connectors (gold, nickel, etc.)
Automobiles: Various parts such as body parts, bumpers, wheels, emblems, etc. (chrome plating, etc.)

Plating is used in everyday items

Purpose of plating

Decoration	・Beautify the appearance ・Convert from base metal to precious metal Examples: ornaments, watches, car emblems, etc.
Protection of the underlying metal	Protect with more corrosion-resistant metals. Examples: steel plates, screws, bolts, etc.
Function Addition	・Harden the surface (hard chrome plating, etc.) ・Allow electricity to flow ・Reflects light ・Repels water (water repellent plating) ・Bonds objects together (e.g., solder plating)

Plating Types

Electrolytic plating

A metal is deposited on the cathode by donating electrons from the outside. Electrolytic plating requires the product to be conductive, and electrolytic plating is not possible on non-conductive materials.

Most Kyocera connectors are plated using electrolytic plating.

Electrolytic Plating Mechanism

Electroless plating

Metals are deposited by the donation of electrons by the reducing agent in the plating solution. In electroless plating, plating is applied simply by immersion, but depending on the material to be plated, some materials can be plated directly and others, such as resins, cannot be plated without a catalyst.

Electroless Plating Mechanism

Plating Materials

If alloyed, elements other than those shown below can also be precipitated.
（Example: Ni-P, Ni-B, Ni-W or Mo, Cd-Te, Cu-In-Ga-Se etc.）
In addition, if non-aqueous systems (organic solvents, molten salts, etc.) are used, metals such as Mg and Al can also be plated.

Periodic table

Why Do Connectors Need Plating?

To give copper-based connectors the properties of other metals (corrosion resistance, solderability, etc.).

Plating

Types and functions of plating used for connectors

Types and Functions of Plating Used for Connectors

Summary

The reason for plating the contacts of connectors is to give them functionality.

Function of plating in connectors

By using "Ni base + Au plating" or "Ni base + Sn-based plating" for Cu-based material, it is possible to create contacts that meet all of the functions required of connectors, such as solder wettability, corrosion resistance, low contact resistance, and electrical conductivity.

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Comprehension Test

Q1. Which of the following types of plating is used on many Kyocera connectors?
　　(1)Electrolytic Plating　　(2)Substitution Plating　　(3)Hot-Dip Plating

Q2. What is the purpose of Au (gold) plating on connector terminals?
　　(1)Harden the surface　　(2)Reflecting light　　(3)Adding electrical conductivity

Answer (Click to Check)