PCB Surface Finishes

The PCB surface finish is one of the final stages of the PCB manufacturing process, and choosing the right finish for a PCB is critical for the assembly of the components on the board and can directly impact the PCBA process, quality, reliability and longevity.

The surface finish covers the exposed copper on the board’s surface, in order to prevent oxidation. Moreover, the surface finish acts as a solderable surface enabling the assembling (soldering) of the components to the board. For fine-pitch components the need for a thin, co-planar coating becomes even more essential.

The chosen surface finish also affects the durability and shelf life of the board,

The PCB surface finish chart below allows for easy comparison of the critical parameters, ensuring selection of the most appropriate finish depending on specific needs and requirements.

  • Properties
  • OSP

    OSP

    Organic Surface Protection (ENTEK)

  • HAL

    HAL

    Hot Air Levelling, Pb Free (Optional non PB Free HAL), not preferred for fine pitch due to thickness variation

  • Immersion Ni/Au

    Immersion Ni/Au

    Immersion Nickel Gold, ENIG

  • Immersion Ag
  • Immersion Sn
  • Immersion Ni/Pd/Au

    Immersion Ni Pd/Au

    Immersion Nickel Palladium Gold, ENEPIG

  • Thick gold

Production

  • Process Effort
  • Low
  • Medium
  • Medium
  • Medium
  • Medium
  • Medium
  • High
  • Planarity
  • Yes
  • No
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Thickness indication
  • 0,2μm
  • 3-25μm
  • Ni 3–5μm Au 0,05μm
  • Ag 0,125 – 0,65μm
  • 1μm
  • Ni 3–5μm Pd 0,2-0,5μm Au 0,05μm
  • Au 0,7–0,9μm

Application

  • Rigid
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Flex
  • Yes
  • Yes
  • Restricted

    RESTRICTED

    Stiffener to be used to avoid excessive stress on the surface finish due to bending

  • Yes
  • Yes
  • Restricted

    RESTRICTED

    Stiffener to be used to avoid excessive stress on the surface finish due to bending

  • Restricted

    RESTRICTED

    Stiffener to be used to avoid excessive stress on the surface finish due to bending

  • Flex-Rigid
  • Not preferred
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Wire Bonding
  • No
  • No
  • Yes
  • No
  • No
  • Yes
  • Yes
  • Press fit
  • Yes
  • Yes
  • Restricted

    RESTRICTED

    Only in combination with suitable connector, check connector documentation

  • Yes
  • Yes
  • Restricted

    RESTRICTED

    Only in combination with suitable connector, check connector documentation

  • Restricted

    RESTRICTED

    Only in combination with suitable connector, check connector documentation

  • Fine pitch
  • Yes
  • Not preferred
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • HDI - BGA
  • Yes
  • Not preferred
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Multiple Solderability
  • Restricted
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Cost
  • Low
  • Low
  • Moderate
  • Low
  • Low
  • High
  • High
  • Shelf life

    Shelf life

    Storage under the following conditions assumed: Original sealed packaging; Temperature 20-24°C, Relative Humidity 30-40%

  • 3 months
  • 12 months
  • 12 months
  • 6 months
  • 6 months
  • 12 months
  • 12 months
  • Refresh of surface
  • Yes
  • Yes
  • No
  • No
  • Yes
  • No
  • No
  • Handling assembly
  • Gloves preferred
  • Gloves preferred
Surface Finished Selection Chart

Download our Surface Finish Selection Chart

Knowledge Centre

PCB Surface Finishes

PCB Surface Finishes

Surface Finish Selection Chart

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