MIL-G-45204
Gold Plating, Electrodeposited
Purity
Types contain the minimum level, or purity, of Gold. Pure soft gold, used in wire-bonding, is 99.9% pure and has HK below 90.| Type | Purity | Grade | Finish |
| Type I | 99.7% Gold | A, B, or C | Hard Gold |
| Type II | 99.0% Gold | B, C, or D | Hard Gold |
| Type III | 99.9% Gold | Grade A only | Soft Gold |
Hardness
| Grade | Hardness |
| Grade A | Knoop hardness 90 Maximum |
| Grade B | Knoop hardness 91-129 |
| Grade C | Knoop hardness 130-200 |
| Grade D | Knoop hardness 200+ |
If the hardness grade for the gold coating is not specified, Type I shall be furnished at hardness Grade A (Knoop hardness: 90 max) and Type II shall be furnished at hardness Grade C (Knoop hardness: 130 to 200).
Thickness
| Class | Minimum Thickness (inches) |
| Class 00 | 0.00002 inch thick (min) |
| Class 0 | 0.00003 inch thick (min) |
| Class 1 | 0.00005 inch thick (min) |
| Class 2 | 0.00010 inch thick (min) |
| Class 3 | 0.00020 inch thick (min) |
| Class 4 | 0.00030 inch thick (min) |
| Class 5 | 0.00050 inch thick (min) |
| Class 6 | 0.00150 inch thick (min) |
| Advantages |
| 1. Thermal & electrical conductivity |
| 2. Resistance to oxidation |
| 3. Solderable |
| 4. Wire-bondable |
| 5. Infrared reflectivity |
| 6. Heat treatment |
| 7. Masking |
| 8. Plugging |