Uniform Through-Mask Gold Plating
Using the Solstice® GoldPro™ Reactor
You will find high-speed plating in a gold sulfite bath is sensitive to localized flow vectors due to the relatively slow diffusion rate of gold complex ions. As a result, a sub-optimal electrolyte flow profile results in a non-flat plated feature shape. To overcome this issue, most immersion and fountain plating systems require very low plating rates.
Our proprietary Solstice® GoldPro™ reactor generates randomized fluid vectors at the diffusion layer of the wafer. This ensures that the diffusion layer is as thin as practical, and that fluid motion remains directionless. Ultimately, this results in a flat plated feature profile without sacrificing plating rate.
Example of Solstice’s WIF uniformity on through-mask gold plating of a surface acoustic wave (SAW) filter.
Applications
- Bond pad for microLEDs
- VCSEL p- and n-contact plating
- Gold bump
- BAW and SAW Filters
- Air-bridge
- And more…
Features
- Randomized fluid vectoring
- Adjustable diffuser
- Dissolved oxygen control
- Dry-contact, low-maintenance plating rotor
- Customized seal reach
- Continuously filtered chemistry loop
- Optional carbon filtration
- Levitronix pump with LeviFlow
Benefits
- High plating rate and high uniformity
- Extremely uniform field profile
- Maximized bath life
- Seal reach aligns to existing integration
- Continuously cleaner chemistry
- Precise, consistent flow rate control
The single-wafer processing Solstice Platform is available with 8, 4, 3 or 2 chambers in customizable configurations, depending on the applications you require.
Technical Data
| Wafer Sizes | 75-200mm (configurable to non-standard sizes, e.g., 160mm) |
| Wafer Thickness | 150μm to >6mm |
| Wafer Materials | Silicon, GaAs, GaN on Si, GaN on Sapphire, Sapphire, Transparent Substrates, and more |
| Flow Rate | 30-60 lpm (dependent on wafer size) |
| Plating Rate | Up to 1μm/minute (dependent on chemistry) |
| Within-Wafer Uniformity | <3% (range 2*mean) |
| Within-Feature Uniformity | <3% [(max-min) / (max+min)] |
| Wafer-to-Wafer Uniformity | 1% (mean-to-mean) |
| Roughness | <2kÅ |
You will find high-speed plating in a gold sulfite bath is sensitive to localized flow vectors due to the relatively slow diffusion rate of gold complex ions. As a result, a sub-optimal electrolyte flow profile results in a non-flat plated feature shape. To overcome this issue, most immersion and fountain plating systems require very low plating rates.
Our proprietary Solstice® GoldPro™ reactor generates randomized fluid vectors at the diffusion layer of the wafer. This ensures that the diffusion layer is as thin as practical, and that fluid motion remains directionless. Ultimately, this results in a flat plated feature profile without sacrificing plating rate.
Example of Solstice’s WIF uniformity on through-mask gold plating of a surface acoustic wave (SAW) filter.
Applications
- Bond pad for microLEDs
- VCSEL p- and n-contact plating
- Gold bump
- BAW and SAW Filters
- Air-bridge
- And more…
Features
- Randomized fluid vectoring
- Adjustable diffuser
- Dissolved oxygen control
- Dry-contact, low-maintenance plating rotor
- Customized seal reach
- Continuously filtered chemistry loop
- Optional carbon filtration
- Levitronix pump with LeviFlow
Benefits
- High plating rate and high uniformity
- Extremely uniform field profile
- Maximized bath life
- Seal reach aligns to existing integration
- Continuously cleaner chemistry
- Precise, consistent flow rate control
The single-wafer processing Solstice Platform is available with 8, 4, 3 or 2 chambers in customizable configurations, depending on the applications you require.
