Electroless Nickel Electroless Palladium Immersion Gold (ENEPIG)

ENEPIG Plating Services

Electroless nickel plating is an excellent choice for manufacturing processes requiring superior corrosion, wear and abrasion resistance, a more even and uniform coating thickness, and good solderability and ductility. Metal finishing companies have developed several versions of the technique that deliver more reliable results, including electroless nickel immersion gold (ENIG) and electroless nickel electroless palladium immersion gold (ENEPIG) plating.

As a leading metal finishing innovator for more than 90 years, Sharretts Plating Company has developed an advanced ENEPIG plating process that can add significant value to printed circuit boards (PCBs). We can deliver customized results that meet your specific manufacturing requirements.

What Is ENEPIG?

It's important to become familiar with ENIG to help you understand ENEPIG plating. The former consists of a double-layer metallic coating. Nickel serves as a barrier to an underlying copper layer and a surface for soldering components. An additional gold layer protects the nickel.

ENIG works well for complex components where flat surfaces are essential, such as flip chips and ball grid arrays (BGAs). This coating also meets the lead-free specifications that many industries now require. On the downside, ENIG can be expensive and doesn't deliver reliable results for rework applications.

ENEPIG surface finishing has been around since the 1990s but didn't gain widespread acceptance until the next decade due to the volatility of precious metals pricing.

While ENEPIG features the same substrate-copper-nickel foundation as ENIG, it includes a layer of palladium between the nickel and gold coatings. Palladium is a hard precious metal that covers the underlying nickel layer and provides extra corrosion protection.

The ENEPIG preparation process entails depositing a layer of nickel at a thickness of 3-5 μm followed by a palladium coating at 0.05-0.1μm. The final step involves the layering of immersion gold at 0.03-0.05 μm.

What Are the Benefits of ENEPIG Plating?

ENEPIG surface finishing offers multiple benefits when manufacturing PCBs, including several advantages over ENIG:

• Prevents "Black Pad": Black Pad syndrome happens when the nickel layer dissolves and corrodes the gold layer. With ENEPIG, the palladium acts as a barrier between the two that prevents this phenomenon from occurring.
• Improves solderability: The extra hardness provided by the palladium layer enhances the quality of the solder joints. The palladium also increases the wire bonding capacity and reduces friction that can cause premature wear.
• Lowers costs: The addition of palladium requires a thinner layer of gold, which can reduce the overall project cost.
• Simplifies the manufacturing processes: ENEPIG also reduces overall PCB thickness, making the soldering and assembly process less complicated and easier to execute.
• Reduces porosity: In metal finishing, porosity refers to small holes that form in an electroplated product. The layering of gold, palladium and nickel helps prevent these defects from reaching the underlying copper coating.
• Maintains compliance: The ENEPIG process is lead-free and meets the stringent Restriction of Hazardous Substances Directive (RoHS) guidelines, ensuring your business remains compliant.
• Minimizes signal interference: Nickel can sometimes disrupt the high-frequency signals produced by PCBs. The palladium in the ENEPIG finishing process can negate the impact of the underlying nickel layer.

Common Applications for ENEPIG Plated Components

ENEPIG plating can protect and enhance the performance of PCBs used in the following industries and many others:

• Medical devices: ENEPIG helps medical device manufacturers meet patient health and sanitation standards when producing equipment such as infusion pumps, pacemakers, medical imaging systems, and blood glucose and blood pressure monitors.
• Consumer electronics: PCBs play a prominent role in the function of various consumer electronics. ENEPIG-plated components add value to smartphones and tablets, personal and business computers, and household appliances like microwaves and refrigerators.
• Aerospace: The PCBs found in many aerospace components must withstand the rigors of harsh operating conditions. ENEPIG finishing can strengthen and protect an aircraft, spacecraft or satellite's power supplies, monitoring equipment and communication devices.
• Automotive: Electronic components have become standard equipment in cars and trucks and control numerous vehicle functions. Auto manufacturers rely on the ENEPIG plating of printed circuit boards found in onboard GPS systems, sound systems, sensors, fuel regulators and more.
• Security: ENEPIG surface finishing helps ensure that PCBs used in security system devices such as cameras, electronic door locks and smoke detectors will function effectively when needed.

Contact SPC for Your ENEPIG Plating Needs

SPC offers premium ENEPIG plating services that will enhance the quality and performance of your parts and components. We're a full-service metal finishing company that can meet your most demanding technical, economical and time-to-market requirements.

Our modern facility contains state-of-the-art electroplating equipment that enables us to plate on all types of metal and plastic surfaces. When combined with our nearly a century of industry expertise, you can feel confident you'll receive results that exceed your expectations.

Contact Sharretts Plating today to learn more about the benefits of our ENEPIG plating process. We'll also provide a free project quote.