Surface Finishes

HOLDING SLOT
HOLDING SLOT
It is common knowledge within the Printed Circuit Board (PCB) industry that each circuit uses copper as the base surface metal...

This is because copper is relatively inexpensive and extremely efficient at conducting electricity: signals can be transmitted across a circuit without losing electricity along the way. However, if left unprotected, copper will oxidise and deteriorate, leaving the circuit board obsolete.

Our range of PCB surface finishes enable two key functions:

  • Protect the exposed copper circuitry from oxidisation
  • Provide a solderable surface when assembling (soldering) the components to the PCB

Read more…



Gold Plating
Silver Plating
Tin Plating
Hot Air Solder Level
OSP
Inks

Electroless Nickel Immersion Gold

(ENIG Plating)

chemical bath for our gold plating process

Description

A two-stage process which extends circuit... (read more)

Often referred to as ENIG plating, this is a two-stage process perfectly suited for manufacturing various styles of Printed Circuit Board (PCB) within aerospace, electronics and medical industries.

The first stage is electroless nickel plating, a chemical process which provides accurate thickness.

The second stage is immersion gold plating, a much simpler process using chemical displacement (direct application) which extends the durability of each copper circuit.

This complete process provides a very flat surface which enables many reflow cycles and a good shelf life.

Typical thickness:
Ni 4µm – 6µm
Au 0.05µm – 0.1µm

This service has evolved over years to become industry gold standard for printed circuit boards and is carried out in-house. It offers outstanding resistance to oxidisation and malleability for sensitive bonding applications, perfectly suited for lead-free solder and/or aluminium wire bonding.

Resources

Electroless Nickel, Electroless Palladium & Immersion Gold

(ENEPIG Plating)

chemical bath for our gold plating process

Description

The same process as ENIG plating but... (read more)

Electroless Nickel, Electroless Palladium and Immersion Gold (ENEPIG) follows the same process as ENIG plating (see above) but with the introduction of a third metallic layer consisting of Palladium (Pd). While the cost is higher than regular ENIG plating, it provides a thinner coat for finer pitch, and prevention of nickel corrosion sometimes associated with complicated boards that require both soldering and wire-bonding. Also, the ENEPIG process enables RoHS compliant soldering.

Typical specifications are:
Ni 3µm – 5µm
Pd 0.1µm – 0.5µm
Au 0.025µm – 0.05µm

Resources

Electroplate Gold (Hard) Over Nickel

chemical bath for our gold plating process

Description

Gold Electroplating, commonly referred... (read more)

Gold Electroplating, commonly referred to as ‘gold plating’, is a chemical process which applies a thin layer of gold over a base metal by applying an electric current to an object within a bath of gold solution. Unlike soft gold plating (see below), additional composites are introduced to the gold to create a harder gold alloy. This, in combination with the use of nickel as a substrate, creates properties best suited to high-friction applications to prevent tarnishing through wear. For example, pin connectors on a PCB.

At EuroTech, we carry out our gold plating in-house. This allows finite control over the design, thickness and quality. Typical values for hard gold plating over nickel include:

Ni 1.0µm – 6.0µm
Au 1.0µm – 3.0µm

Resources

Electroless Gold (Soft) Direct Over Copper

chemical bath for our gold plating process

Description

Electroless soft gold plating is a single... (read more)

Gold Electroless, commonly referred to as ‘gold plating’, is a single-stage chemical process which applies a thin layer of gold over a copper base metal by applying chemical displacement. Unlike hard gold plating (see above), The gold remains ‘pure’ to retain malleability for improved solderability. This creates properties best suited to low-friction, enclosed applications which are not subject to wear.

At EuroTech, we carry out our gold plating in-house. This allows finite control over the design, thickness and quality. Typical values for hard gold plating over nickel include:

Au 0.05µm – 1.0µm

Resources

Immersion Silver

(IAg)

chemical bath for our gold plating process

Description

Creates a thin layer of silver... (read more)

Immersion Silver plating is a simple process which extends the durability of each Printed Circuit Board (PCB), following the same methods as our immersion gold. It creates a protective layer of silver over the outermost surface of the PCB to protect copper elements from oxidisation, offering superior solder joint strength. The use of Immersion Silver has no effect on the assembly processes and improves solderability.

This process is carried out in house using sterling silver II with RoHS compliant soldering.

0.1µm – 0.25µm

Resources

Immersion Tin

(ISn)

immersion tin plate over copper tracce

Description

Immersion Tin is another Lead-free... (read more)

Best suited for press-pin connectors, Immersion Tin (ISn) is another of our chemical displacement processes deemed better for the environment as a Lead-free option. It is not suited for all applications due to a limited shelf life

Some elements of the Immersion Tin process are outsourced, therefore not eligible for our fast turnaround service.

Typical thickness:
Sn 1.0µm – 1.1µm

Resources

Hot Air Solder Level

(HASL)

Hot Air Solder Level Surface Finish

Description

HASL is a protective lead surface... (read more)

Hot Air Solder Leveling (HASL) is a process that applies a protective surface finish of molten lead to the outer layer of the PCB. Excess lead is then dispersed and cooled with heated air. This technique ensures exposed copper surfaces are not damaged during the later stages of a PCB’s fabrication, and also heat-tests a board for potential delamination prior to assembly.

This process is carried out in our Factory.

SnPb 63/37 eutectic tin lead
10µm – 25µm

Resources

Lead-Free Hot Air Solder Level

Hot Air Solder Level Surface Finish

Description

Lead-Free HASL is a protective metallic... (read more)

Lead-Free Hot Air Solder Leveling (HASL) follows the same process as leaded HASL with the exception of the use of lead. A lead-free molten tin-compound is applied as a protective surface finish to the outer layer of the PCB. Excess metal is then dispersed and cooled with heated air. The lead-free option sacrifices durability over regular leaded HASL.

This process is carried out in our Factory.

RoHS compliant soldering is available for some niche applications (eg. aerospace, military and medical industries)
10µm – 25µm

Resources

Organic Solderability Preservative

(OSP)

Circuit Board Holding Image

Description

OSP is a method for coating PCBs... (read more)

Organic Solderability Preservative (OSP) is a way of coating the Cu areas of a PCB preventing oxidation of the Cu.  It uses an organic solution that bonds to the Cu element to protect the Cu until the soldering stages. Today’s OSP offers 12 month shelf life with 3 x multiple soldering capability. With this process the component interconnection is directly with the Cu surface of the PCB offering highest reliability of joint strengths.

We carry out this process in-house at our factory.

Entek / RoHS Compliant Soldering
0.2µm

Resources

Silver Ink

Circuit Board Holding Image

Description

Silver ink is a process which... (read more)

Silver ink is a process which uses developed ink comprised of silver acetate. This is dissolved in ammonia to give a clear solution which is used to form the trace pattern, mainly for use with flexible substrates.

These PCB’s are common within technology markets where flexible screens or antennae are used

Resources

Carbon Ink

Circuit Board Holding Image

Description

What is it and what does it do?

In-House, but very specialised

By Request
Sn ??µm – ??µm

Resources