Discover, Connect & Collaborate at TECHINNOVATION 2021
Ammonia Odour Free PdNi Alloy Deposition Solution
Conventional PdNi alloy deposition solution contains high amount of ammonia (> 50 ml/L) and ammonia salt as complexing agents in the formulations. As a strong alkali (pH> 7) and high volatile, pungent ammonia often evaporate fast at elevated temperatures and releases pungent ammonia odour, both of which is not user safe and environmentally friendly. It is difficult to maintain the pH in the chemical solution, and often affects the solution’s performance. Large amount of ammonia is often used to replenish this loss, and additional safety infrastructure is also needed for this process.
Conventional PdNi alloy deposition solution also requires high amount of palladium (25g/L) to achieve the desirable PdNi alloy (Pd80Ni20 in wt%) deposits at current density 80 ASD. The high amount of Pd increases the manufacturing cost as well as costs for disposal/recovery.
This technology offers an ammonia odour free PdNi alloy deposition solution by SP, with key features/advantages in:
- Reducing the use of ammonia and ammonia-based chemicals by replacing a portion of these key components in conventional solutions with other suitable complexing agents, resulting in ammonia odour free.
- Achieve the same PdNi alloy (Pd80Ni20 in wt%) deposits at current density 80 ASD with lower initial Pd concentrations, hence reducing palladium consumption, manufacturing and disposal cost.
Technology Features, Specifications and Advantages
The revised formulation carries the following specifications:
- Halogen/ammonia odour free and low in ammonia (10-20% lower)
- Require lesser palladium concentration (16 g/L) with nickel concentration (25 g/L) to achieve the PdNi alloy (Pd80Ni20 in wt%) deposits at current density 80 ASD, reducing palladium consumption (reduced up to 9 g/L) and manufacturing cost
- Operating temperature: optimum 45°C (40-50°C)
- Operating pH: 7-7.35
- Under current density 80 ASD, achieved the 0.76 µm thickness of PdNi deposits within 3 seconds
- Time to deposit 1 µm at 10 ASD about 30 seconds
- Applicable to the wide range of operational current density from 10-120 ASD without burn and is applicable to both Direct Current (DC) and pulse deposition
- Having uniform and dense deposit according to SEM images
- Hardness value of the deposits in the range of 550-620 mHv10 for current density 20-120 ASD
- Composition of deposits: 77% (wt) Pd ± 3%
- Low porosity and enhanced corrosion resistance (up to 48 hrs) from neutral salt spray test
- Small grain size 8-13.5 nm from the deposits (denser) which enhance the performance (morphology, hardness and corrosion resistance etc.) thus thinner PdNi deposits required
This technology is suitable for electronic and interconnect devices which require PdNi deposits. Such as electronic components (e.g. connectors) which is miniaturized through the years as less consumption of precious metal (palladium) and thinner deposit with maintainable performance.
Smaller and tighter configuration of electronic components and the miniaturization results in more challenging packaging requirements as well as cost reduction pressure faced by manufacturers required decreased coating thickness for precious metal but maintain similar performance (morphology, hardness and corrosion resistance etc.)
The market size for connector is foreseen to be at least 70 billion with annual grow rate of 4%: https://www.ttiinc.com/content/ttiinc/en/resources/marketeye/categories/connectors/me-bishop-20190313.html
- Reduced precious metal consumption (lesser 9 g/L corresponding to USD 560/L)
- User and environmentally friendly as ammonia odour is not generated
- Applicable to the wide range of operational current density without burn, allowing the use of high ASD to shorten operation time and increase productivity
- Low porosity and denser deposit, enhancing performance in term of morphology, hardness and corrosion resistance.