PCB SURFACE FINISHES

By Grant Main

The PCB surface finish is one of the final stages of the PCB manufacturing process. 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, shelf life and cost of the board.

Read our guide to the different types of surface finishes by clicking this link.

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

  • Electrolytic Au Soft
  • Electrolytic Au Hard

Production

  • Process Effort
  • Low
  • Medium
  • Medium
  • Medium
  • Medium
  • Medium
  • High
  • High
  • Planarity
  • Yes
  • No
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Thickness indication
  • 0,2μm
  • 3-25μm
  • Ni 3–5μm Au 0,04μm - 0.1μm
  • Ag 0,125 – 0,65μm
  • 1μm
  • Ni 3–5μm Pd 0,2-0,5μm Au 0,05μm
  • Class 1 and 2 Ni min 2um Au min 0.8um Class 3 Ni min 2.5um Au min 1.25um 0.8um
  • Class 1 and 2 Ni min 3um Au min 0.3um Class 3 Ni min 3um Au min 0.8um

Application

  • Rigid
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Flex
  • Yes
  • Not Recommended
  • 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

  • Restricted

    RESTRICTED

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

  • Rigid Flex
  • Not preferred
  • Not Recommended
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Wire Bonding Al
  • No
  • No
  • Yes
  • No
  • No
  • Yes
  • Yes
  • No
  • Wire Bonding Au
  • No
  • No
  • No
  • No
  • No
  • Yes
  • Yes
  • No
  • 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

  • Restricted

    RESTRICTED

    Only in combination with suitable connector, check connector documentation

  • Fine pitch
  • Yes
  • Not preferred
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • HDI - BGA
  • Yes
  • Not preferred
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Multiple Solderability
  • Restricted
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Yes
  • Cost
  • Low
  • Low
  • Moderate
  • Low
  • Low
  • High
  • 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
  • 12 months
  • Refresh of surface
  • Yes
  • Yes
  • No
  • No
  • Yes
  • No
  • No
  • No
  • Handling assembly
  • Gloves preferred
  • Gloves preferred
Surface Finished Selection Chart

Download our Surface Finish Selection Chart

Knowledge Centre

Optimised PCB Design – Design Rules In Your Layout System

Optimised PCB Design – Design Rules In Your Layout System

Explore more
CHOOSING THE APPROPRIATE VIA FILLING/PLUGGING TYPE FOR YOUR PCB

CHOOSING THE APPROPRIATE VIA FILLING/PLUGGING TYPE FOR YOUR PCB

By Sam liu

Explore more
Fördelar och användning av värmeavledning

Fördelar och användning av värmeavledning

By Jörgen Paulsson

Explore more
What are Thermal Pads in PCB?

What are Thermal Pads in PCB?

By Jörgen Paulsson

Explore more
How to avoid Bow and Twist in your PCB

How to avoid Bow and Twist in your PCB

By Thomas Wernsdörfer

Explore more
PCB Manufacturing Process

PCB Manufacturing Process

PCB Manufacturing Process, how we ,design, develop and produce Printed Circuit boards.

Explore more
PCB Raw Materials Guide

PCB Raw Materials Guide

By Maysa Salameh

Explore more
The Importance of Impedance Control in PCB Design

The Importance of Impedance Control in PCB Design

By Michael Schmitz

Explore more
Micro Via Technology

Micro Via Technology

By Boy van Veghel

Explore more

We're here to help

 From engineering advice to selecting the right manufacturing partner for
you – our experience and expertise gives you the right solution. 

Get in touch and let’s start working together.