Electrical Properties of Plating
What Are Electrical Properties?
The electrical properties of plating are a general term for the characteristics that control how easily electricity flows, how it is blocked, and how stable it remains. With the spread of 5G communications, EVs, and IoT devices, the requirements for these properties continue to rise year after year. This article covers four properties: conductivity, low contact resistance, EMI shielding, and high-frequency performance.
Conductivity
Conductivity refers to the ability of a plated layer to transfer electricity efficiently with low resistance. It plays a critical role in components that demand high conductivity, such as EV busbars, power terminals, high-current connectors, and solar cells.
Silver, copper, and gold plating are typical choices, and their conductivity depends on the combination of coating thickness and purity.
Low Contact Resistance
The role of low contact resistance is to minimize electrical loss occurring between contact points. It is required for components where even slight signal loss becomes a problem, such as electronic connectors, relay contacts, and IC sockets.
Gold plating, palladium, and silver plating are recommended, but because oxide film formation increases resistance, balancing conductivity with oxidation resistance is a key design challenge.
EMI Shielding
EMI shielding is the function of reflecting or absorbing external electromagnetic interference (EMI/RFI) to block interference both into and out of a device. It is essential in demanding applications where electromagnetic interference directly causes malfunctions, such as medical electronics, military communication equipment, and automotive ECUs.
In addition to nickel, silver, and copper, nickel-copper composite plating is used, and shielding effectiveness varies with coating thickness and conductivity.
High-Frequency Performance
This property addresses the skin effect, in which high-frequency current concentrates near the conductor surface, and serves to prevent signal loss. It is indispensable for 5G antenna components, millimeter-wave communication modules, and radar components.
Typical choices include silver, gold (balancing oxidation resistance and conductivity), and copper plating as an underlayer. In high-frequency bands, both surface conductivity and smoothness determine signal quality.
Comparison of Properties
The four electrical properties are summarized below. It is important to define application-specific requirements from the early stages of design.
| Property | Key Benefits | Typical Applications | Recommended Plating |
|---|---|---|---|
| Conductivity | Carries high current with low resistance | EV busbars, power terminals | Silver, copper, gold plating |
| Low contact resistance | Prevents signal loss at contact points | Connectors, relays, switches | Gold plating, palladium, silver |
| EMI shielding | Blocks EMI/RFI interference | Medical devices, automotive ECUs | Nickel, copper, silver |
| High-frequency performance | Preserves signal quality in 5G and high-frequency bands | 5G antennas, radar components | Silver, gold plating, copper (underlayer) |
Same Material, Different Results: Not Every Company Can Deliver the Right Plating Process
Even when the same plating type is specified on paper, whether purity can be maintained and surface roughness properly controlled depends on the process control capabilities of the plating company.
Controlling electrical properties requires integrated management of coating thickness, purity, and smoothness, so it is important to choose a company with a concrete track record. When selecting a supplier, we also recommend referring to "3 Recommended Functional Plating Companies by Industry and Component."
Functional Plating Services
by Industry
and Component Type
Semiconductor Components
“We need a shop for difficult plating others declined.”
Japan, est. 1931
- Precious Metal Plating
for Micro Components - Mitsuya supports uniform precious metal plating on parts down to 0.1 mm in diameter. This can help improve precision and durability in semiconductor inspection equipment.
- High-Adhesion Plating
for Tips and Contacts - Mitsuya has developed an in-house process for titanium and tungsten that does not require heat treatment. It can support high-adhesion plating on pin and card contact areas.
- Support for New Product Development
- Engineers can consult Mitsuya before semiconductor IC specifications are finalized and verify performance through prototypes. This can help reduce development risk and rework costs.
- Electronics and Telecommunications
- Semiconductor Inspection Equipment
- Space Development
Automotive Components
“We need 10 million parts delivered on time, every time.”
U.S., est. 1932
- Consistent Quality and
Lead Times at Volume - Greystone has an annual mass-production record of 130 million automotive parts*1 through machining and plating.
- Single-Source Support from Processing through Plating
- Machining and plating are completed within the same group. Fewer delays between processes can help reduce costs.
- Quality Standards
Automakers Trust - All U.S. locations are IATF 16949 certified, with plating process control that meets OEM quality standards.
- Automotive
- Firearms
Aircraft
Components
“Nadcap is required. We need proven certification experience.”
U.S., est. 1960
- Smoother Approval
from Major Primes - An approved supplier to Boeing, Lockheed Martin, and others, with more than 80 Nadcap-accredited processes.
- Aerospace & Defense Work on a Certification-First Basis
- Proven across a wide range of mission-critical components, including missiles and fighter aircraft.
- Meets Defense Standards, Even the Strictest
- Its cadmium-replacement zinc-nickel plating won a 2020 Secretary of Defense Environmental Award and has been used on the F-35*2.
- Aerospace and Defense
- Medical Devices
*2 Source: Anoplate official website https://www.anoplate.com/news-and-events/zinc-nickel-plating-highlights-2020-secretary-of-defense-environmental-award/