This section of JIS defines gold and gold alloy plating with the thickness of at least 0.2 µm on a metal or nonmetal substrate, produced for engineering purposes, including electrical / electronic products, machinery and other functional components.

(1) Definition of terms

1. Gold plating

Soft gold plating refers to electroplating with its gold content being 99.9% or more.

2. Gold alloy plating

This refers to electroplating with its gold content being 58.8% or more but no more than 99.9%. This plating is harder compared to the gold plating described earlier.

3. Multi-layer gold or gold alloy plating

This refers to plating comprised of two or more layers with different gold content.

(2) Quality

Here are the assessment items for determining the quality of plating films.

1. Appearance

Check the quality of polish, radiance and color, along with imperfections as roughness, burnt parts or pits.

2. Plating thickness

The minimum plating thickness is classified as follows:

[Table] Classification by the minimum plating thickness

3. Gold content in plating

4. Porosity of plating

Nitric acid aeration test (explained in another volume)

5. Resistance to discoloration by heating

Applicable to thick plating (explained in another volume)

6. Corrosion resistance of plating (explained in another volume)

7. Plating adhesion

8. Solder wettability of plating

9. Residual salt on significant plating surfaces

10. Electrical properties of plating

11. Plating hardness

12. Abrasion resistance of plating

(3) Plating name

Plating names are described by the symbols shown in this table.

In the next volume, we will learn testing methods of nitric acid aeration test, color fastness test by heating, and hydrogen sulfide test for industrial gold and gold alloy plating.