XEKERA
Get a Quote

ENIG Surface Finish

Electroless Nickel Immersion Gold (ENIG) is the industry-standard surface finish for high-reliability PCBs. ENIG provides a flat, solderable surface with excellent shelf life, making it ideal for fine-pitch components and complex assemblies.

Why Choose ENIG?

Flat Surface

Perfectly flat surface ideal for fine-pitch components and BGA packages.

Long Shelf Life

Excellent shelf life with minimal oxidation, ideal for long-term storage.

Superior Solderability

Excellent wetting characteristics for both lead-free and leaded solders.

RoHS Compliant

Fully compliant with RoHS and REACH environmental regulations.

ENIG Layer Structure

Immersion Gold (Au) 0.05-0.23 µm (2-9 µ-inch) - Protects nickel from oxidation and provides solderable surface
Electroless Nickel (Ni) 3-6 µm (120-240 µ-inch) - Provides diffusion barrier and structural support
Copper Base Material PCB copper traces and pads

Technical Specifications

Standard Thickness
  • Nickel: 3-6 micrometers (120-240 µ-inch)
  • Gold: 0.05-0.23 micrometers (2-9 µ-inch)
  • Typical gold: 0.08-0.13 micrometers (3-5 µ-inch)
  • Phosphorus content in Ni: 6-9%
Performance Characteristics
  • Shelf life: Up to 12 months
  • Multiple reflow capable (6 or more cycles)
  • Operating temperature: -55°C to +125°C
  • Contact resistance: under 10 mΩ

Ideal Applications

  • Fine-Pitch Components: BGAs, CSPs, QFNs, and other fine-pitch packages requiring flat surfaces
  • High-Density Interconnect (HDI): Microvia filling and fine-line routing applications
  • Wire Bonding Applications: Gold wire bonding on chip-on-board assemblies
  • Press-Fit Connectors: Reliable electrical contact for board-to-board connections
  • Long-Term Storage: Products requiring extended shelf life before assembly

Our ENIG Process Control

We maintain rigorous process control to prevent common ENIG defects such as black pad syndrome:

  • Automated bath chemistry monitoring and control
  • Regular nickel phosphorus content testing
  • XRF thickness measurement on every panel
  • SEM cross-section analysis for process qualification
  • Solder joint pull testing to IPC-4552 standards

Industry Standards Compliance

IPC-4552
IPC-4556
J-STD-001
IPC-A-600

Industry-Standard Surface Finish

ENIG is the proven choice for high-reliability PCBs. Contact us to learn more about our ENIG capabilities and quality control processes.

Request ENIG Quote