Knowledge Base
Sprint-Layout
CadSoft
BPECS32
CAM Tooling Services
PCB Elegance
CIRCAD
ORCAD
PowerEsim
LAYOUT
CIRCUIT LAYOUT
QCAD
POWERPCB
DREAM CAD
PCB ASSISTANT
QUICK ROUTE
E-CAD
PCB DESIGNER
TARGET 3001
WIN CIRCUIT 98
DESIGN WORKS
OSMOND PPC
VUTRAX
LAY01
SCORE
VISUALPCB
WINBOARD
UL TIBOARD
PROTEUS
EPD-Electronics Packaging Designer
AutoTrax Eda
PCB Surface Processes
Purpose of PCB Surface Finish
*Provides a solderable surface for Component assembly.
*Protect Copper Surface from Oxidation.
*Provide a surface appropriate for wear related parts.
High Performance Surface Finish
*Mixed Technology Board Designs
*Solderable,SMT and Thru-hole
*Wire Bondable
*Contact Resistance
*Co-Planar Surfaces
*Compatability with variety of fluxes & paste
*Cost effective
*Environment
Available Surface Finishes
*Electroless Nickle-Immersion Gold
*Immersion Silver
*Hot Air Solder Level
*Organic Solderability Preservative
*Electrolyte Nickel – Hard Gold
*Electrolyte Nickel – Soft Gold
Surface Finish Details
*Electroless Nickel-Immersion Gold (ENIG)
A two layer, gold over nickel, metallic surface finish plated onto the copper base by means of a chemical decomposition process
Advantage:
- Typical Thickness: 3-8 uin gold over 150-250
- uin nickel
- Excellent Corrosion resistance
- Good for aluminium wire bonding
- Excellent flatness for fine-pitch technology
- Excellent Solderability
- Excellent shelf life(12 mo)
- Good surface contrast
- Good contact resistance
- High Aspect Ratio Capability
Disadvantage:
- Narrow process window
- Higher cost than HASL(1.5 to 2.0 times)
- Back pads: brittle solder joints
- Fatigue failures on large BGA packages
- Skip plate
- Extraneous nickel plating
- Solder mask capability with the nickel bath