Printed circuit board surface finish application is one of the final steps in the manufacturing process and is designed to prevent oxidation of the remaining exposed copper. Selecting the appropriate surface finish is a critical material decision due to importance it plays in electronic assembly. The surface finish will influence the cost, manufacturability, quality, and reliability of the final product.

The chart below lists many of the surface finish options offered by Bay Area Circuits and provides some information regarding the characteristics and applications for each. If you’re unsure which surface finish is best for your project, contact us and we’ll be happy to assist you.

 

Characteristics

HASLHASL (LF)ENIGENEPIGHARD GOLDSOFT GOLDSILVEROSPWHITE TIN
Deposit DippedDippedImmersionImmersionElectrolyticElectrolyticImmersionDipped Immersion
 Process Control PoorPoorFairFairFairFairFairPoor/Fair Fair
Process CostLowLowMediumHighHighHighMediumLow Medium
SMTDomeDomeFlatFlatFlatFlatFlatFlat Flat
Thin Board FinishNoNoYesYesYesYesYesYes Yes
Thermal Cycle (times)>2>3>2>2>2>2>2~2 >2
Shelf LifeLong
(1+ Yrs)
Long
(1+ Yrs)
Long
(1+ Yrs)
Long
(1+ Yrs)
Long
(1+ Yrs)
Long
(1+ Yrs)
Medium
(9-12 Mos)*
Medium
(9-12 Mos)*
Medium
(9-12 Mos)*
HandlingNormalNormalNormalNormalNormalNormalCriticalCritical Critical
Exposed CopperNoNoNoNoYesNoNoYes No
Contact ApplicationsNoNoYesYesYesYesNoNo No
Thickness25 – 2000 μin25 – 2000 μin3 – 10 μin of Gold over 150 – 200 μin of Nickel1 – 2 μin of Gold over 4 – 8 μin or 8 – 15 μin Palladium over 100 -150 μin Nickel98% Pure, 23 Karat 30 – 50 μin over 100 – 150 μin of Nickel99.99% Pure, 24 Karat 30 – 50 μin over 100 – 200 μin of Nickel6 – 18 μin 8 – 24 μin25 – 60 μin

Application

 HASLHASL (LF)ENIGENEPIGHARD GOLDSOFT GOLDSILVEROSPWHITE TIN
RoHS CompliantNoYes Yes Yes Yes Yes Yes Yes Yes 
Fine Pitch SMTNo No Yes Yes Yes Yes Yes Yes Yes
BGA & μBGA No No Yes Yes Yes Yes Yes YesYes
Flip Chip No No Yes Yes Yes Yes Yes Yes Yes
Wire Bonding No No Yes (Al)Yes No Yes (Au) No No No 
Contact / Connector No NoYes Yes Yes No No No No 
High ReliabilityHigh Low/Medium High High Medium/High High Medium/High Medium/High High 
Solder Joint IntegrityExcellent Good Good Good Poor Poor Excellent Good Good 

 

*Requires Unique Storage Techniques

μin = Microinches