When it comes to gold plating, not all finishes are the same. Both hard and soft gold offer unique properties that can influence performance, durability, and overall results, but each features their own unique attributes.
If you’re comparing the two options, understanding the basic differences and common applications of each is a great first step in choosing the right gold plating for your needs.
Understanding the Differences Between Hard and Soft Gold Plating
Hard Gold Plating
Used for electrical contacts, connectors, wear surfaces
| Gold Purity | 99.0 – 99.7% |
|---|---|
| Alloying Elements | Nickel and Cobalt |
| Hardness | 130–200 HK |
| Wear Resistance | Excellent |
| Conductivity | Slightly less than soft gold |
| Contact Resistance | Slightly higher than soft gold |
| Bondability (Wire Bonding) | Poor / unacceptable |
| Solderability | Fair to poor |
| Au/Sn, Au/Ge Brazing | Poor / unacceptable |
| Corrosion Resistance | Very good, slightly reduced vs soft gold |
Soft Gold Plating
Used for parts requiring: Wire bonding, die attach, and soldering.
| Gold Purity | ≥ 99.7% (most often 99.9%) |
|---|---|
| Hardness | 60–90 HK |
| Wear Resistance | Poor |
| Conductivity | Excellent |
| Contact Resistance | Extremely low |
| Bondability (Wire Bonding) | Excellent |
| Solderability | Excellent |
| Au/Sn, Au/Ge Brazing | Excellent |
| Corrosion Resistance | Excellent |
Key Applications
Hard and soft gold plating are chosen for different needs, with selection depending on how a given part will function. Hard gold plating is commonly used on components that physically interact with switches, connectors, relay contacts, and other similar parts. These types of applications benefit from a harder finish that can stand up to mechanical stress without significant wear.
Soft gold plating is typically selected when the plated surface serves an electrical purpose, rather than a mechanical one. It is frequently for semiconductor packages and other components where forming a reliable electrical pathway is highly important.
Selecting the Right Gold Plating for Your Needs
Choosing between hard and soft gold plating depends on how the gold finish needs to operate within your design. Here are some factors you should consider when evaluating options:
- Contact or bonding method
- Level of mechanical interaction
- Required electrical characteristics
- Operating environment or exposure conditions
- Expected product lifespan and reliability needs
Reviewing these details with a plating expert can help confirm the best finish for your application.
Choose General Metal Finishing for All Your Gold Plating Needs
At General Metal Finishing, we offer both hard and soft gold electroplating services with processes that are supported by comprehensive quality certifications to meet industry and customer requirements.
Here’s what you can expect from our soft and hard gold plating services:
- Multiple plating methods – Barrel plating, rack plating, and vibratory plating
- Industry-recognized gold specifications – ASTM B488, MIL-G-45204, MIL-DTL-45204
- Gold plating experience across industries – Electronics, medical, industrial, aerospace and defense, and more
Contact Us Today
If you need further assistance in choosing between soft and hard gold plating, our experienced team is here to help. We can review your requirements, talk through the performance goals of your components, and recommend the best finish for your application.
Please get in contact with us today. We look forward to assisting you with your gold plating needs.