Laminates & Hybrid Materials
+ Final Finishes
Panelization Guideline

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Technology Resource Center: Final Finish Alternatives

Westak provides alternative final finish processes that offer improved board integrity, dimensional stability and final assembly reliability advantages for fine-pitch, BGA, surface mount and plated through hole boards. These new alternatives to HASL offer a planar surface for better component placement as well as numerous other advantages. Westak has been able to overcome many limitations of the HASL process while maintaining and improving printed circuit board manufacturability and the quality of surface mount printed circuit boards.

  HASL OSP ENIG ENEPIG Soft Gold Silver White Tin Lead Free HASL
SMT Dome Flat Flat Flat Flat Flat Flat Dome
Solderability (as received) Good Good Good Good Good Good Good Good
Thermal Cycle (times) >2 ~2 >2 >2 >2 >2 >2 >3
Shelf Life Long Medium Long Long Long Medium Medium Long
Handling Normal Critical Normal Normal Normal Critical Normal Normal
Exposed copper No Yes No No No No No No
Thin Board Finish No Yes Yes Yes Yes Yes Yes No
Contact Applications No No Yes AU/Al Wire Bonding AU/Al Wire Bonding No No No
Waste Treatment & Safety Poor Good Fair Fair Fair Fair Fair Poor
Process Control Poor Fair/Poor Fair Fair Fair Fair Fair Poor
Process Cost Medium Low High High High Medium Med/Low High

Application

  HASL OSP ENIG* ENEPIG Soft Gold** Silver* White Tin* Lead Free HASL**
Fine Pitch SMT No Yes Yes Yes Yes Yes Yes No
BGA & μBGA No Yes Yes Yes Yes Yes Yes No
Flip Chip No Yes Yes Yes Yes Yes Yes No
Wire Bonding No No Yes Yes Yes Yes No No
Contact/Connector No No Yes Yes Yes No No No
High Reliability High Medium High High High Med/High Medium Low/Med

*Immersion Process
**Available Ni/Pd/Au