Introduction
High reliability for electronic systems/assemblies is critical for various industry sectors and their continued success. Electronic devices include Printed Circuit Board (PCB) as the key component for optimal operation/performance. Selection of the materials used in PCBs is critical to make the assemblies highly reliable and free from corrosion.

Conventional Solution
Among the primary factors affecting the reliability of electronic systems is the surface finish applied on PCB copper pads – a need commonly met by technology manufacturers through the Electroless Nickel Immersion Gold (ENIG) process.

Conventional ENIG currently available in the market is prone to black-pad defects associated with de-wetting of solder. The root cause of black-pad defects has been identified as hyper corrosion activity at Gold (Au) and Nickel-Phosphorous (Ni-P) interface which involves Nickel depletion and an enrichment of Phosphorous in localized areas.

ENIG also suffers from brittle solder joint failures. When the soldering is done at 260°C, too much Nickel (Ni) diffuses into the solder joint. That’s why conventional ENIG solder joints usually see brittle field failures and reliability concerns of electronic assemblies - component disconnection which lead to overall malfunction of electronic assemblies.

Moreover, most ENIG manufacturers/suppliers provide cyanide-based Gold chemistry which has health and ecological hazards.

Existing substitute surface finishes are either very expensive or do not resolve these issues fully, and/or they can compromise other key properties.

ENIG-Premium
ENIG-Premium is an innovative, cost-effective, eco-friendly solution that achieves robust solder joints, eliminates black pads-corrosion related issues, and provides improved quality & reliability of electronic assembly. This technology is a potential replacement for existing ENIG (with market value roughly about 2-3 billion USD/year).

ENIG-Premium involves inclusion of a proprietary barrier layer (nano-engineered) at the Ni-P and immersion Gold interface which leads to smoothening of the Ni-P interface and passivation of the surface which increases corrosion resistance by 10x. Then, when our proprietary immersion Gold deposits onto the barrier layer-treated Nickel, there's no black pad formation [Img2 and Img3].

The barrier layer helps attain robust solder joints by minimizing the intermetallic thickness [Video1] and preventing Nickel atom diffusion even after long thermal exposure (aging). This results in robust solder joints and manufacturing of PCBs & electronic assemblies of the highest reliability.

Moreover, ENIG-Premium is cost-effective due to minimal use of precious metal (Gold) and uses cyanide-free chemistry for immersion Gold process making it eco-friendly. This allows manufacturers to consume eco-friendly product while avoiding major field failures.

Conclusion
Ensuring robust solder joints and elimination of black-pad related failures with the ENIG-Premium can help to lead to improved reliability of electronic assemblies for various industry sectors. Our premium nano-engineered formula alleviates any issues with conventional ENIG. These benefits will help manufacturers to avoid major failures and the resulting consequences.