Typically, three gold types are used in the gold plating process; 99.0%, 99.7% and 99.9% with four grades of hardness from 91 Koop to 201 Koop and over. Depending on your gold plating application, different levels of thickness are available from 5 to 1500 micro inches. Electrum recommends high purity soft gold plating between 50 and 100 micro inches for the best soldering and uses 99.9% gold only at hardness grade of 90 Koop. Our experienced staff can advise you on what gold plating service is appropriate for your products.
Gold plating is an electrodeposit process that produces a product with the following physical properties:
- Yellow to orange color
- Matte or bright finish
- Good corrosion resistance
- High tarnish resistance
- Excellent conductor
- Exceptional solderability
If the hardness grade for the gold coating is not specified, type 1 shall be furnished at hardness grade A, and type 2 at grade C.
For soldering, a thin high purity soft gold coating is preferred. A minimum thickness of 0.000050 inch and a maximum thickness of 0.00010 inch shall be plated.
Gold |
MIL-G-45204 |
| Type I |
|
99.7% gold min. (Grade A,B,C) |
| Type II |
|
99.0% gold min. (Grade A,B,C) |
| Type III |
|
99.9% gold min. (Grade A only) |
| Grade A |
|
90 Knoop max. |
| Grade B |
|
91-129 Knoop |
| Grade C |
|
130-200 Knoop |
| Grade D |
|
201 Knoop and over |
| Class 00 |
0.00002” min |
|
| Class 0 |
0.00003” min |
|
| Class 1 |
0.00005” min |
|
| Class 2 |
0.00010” min |
|
| Class 3 |
0.00020” min |
|
| Class 4 |
0.00030” min |
|