【Popular Science】The Tiny Electroplated Layer Determines The Upper Limit Of Terminal Quality
- Categories:News
- Author:Guangdong Deke Electric Co., Ltd.
- Origin:https://www.de-ke.cn/
- Time of issue:2026-05-26 09:58
- Views:
【Popular Science】The Tiny Electroplated Layer Determines The Upper Limit Of Terminal Quality
- Categories:News
- Author:Guangdong Deke Electric Co., Ltd.
- Origin:https://www.de-ke.cn/
- Time of issue:2026-05-26 09:58
- Views:
Terminals,as the core components for connecting electronic circuits,are responsible for the transmission of current and signials.The plating process directly determines the performance,lifespan,and stability of terminals,and the details of the coating process profoundly affect the operational quality of electronic products.
1.Why Must Terminals Be Plated?
Terminal materials are usually made of brass or phosphor bronze to ensure good elasticity and electrical conductivity. However, copper has a fatal drawback: it is highly prone to oxidation. Once the copper surface oxidizes to form cuprous oxide, the contact resistance increases sharply, leading to device heating and signal interruption. Therefore, the primary task of plating is to isolate the air and provide a stable contact interface.
2.Three Major Mainstream Electroplating Processes: Gold, Nickel, Tin
In the field of connectors, gold plating, nickel plating, and tin plating each have their specific roles, and sometimes collaboration is required; for example, nickel plating is needed before gold plating.
a.Nickel Plating
Many people mistakenly believe that the surface of the terminal is gold-plated, but the underlying layer is usually silvery nickel. Is the nickel layer necessary? In high-end applications, yes. The nickel layer has strong adhesion, can firmly bond to the substrate, prevent impurities in the substrate from precipitating, enhance the bonding strength of the upper tin or gold plating, improve the overall hardness and deformation resistance of the terminal, and provide a solid foundation for rust prevention and protection.
b.Gilding
Gold is a precious metal with extremely stable chemical properties and hardly reacts with other substances. The application scenarios for gold plating are generally high reliability, low voltage, and small signals. For example, medical equipment, aerospace, and internal board-to-board connectors in 5G base stations.
c.Tin Plating
Tin plating is the most widely used electroplating process for conventional terminals in both civil and industrial applications. The coating offers excellent solderability, allowing for easy and secure welding, balanced electrical conductivity, and a smooth surface that reduces insertion and removal resistance. At the same time, it provides oxidation resistance and mild corrosion protection to meet everyday operational requirements, offering a very high overall cost-performance ratio.



3.Product Inspection — Six Checkpoints to Ensure Quality
The terminals after electroplating must undergo the following six inspections, and can only be shipped if all are passed:
- Film Thickness Testing: Use an X-ray fluorescence analyzer to check whether the thickness of the gold plating and nickel plating meets the standard (e.g., gold plating ≥0.38 μm, nickel plating ≥1.27 μm). This is the most basic and also the most important inspection item.
- Adhesion Test: Check whether the coating exhibits peeling or flaking by performing a 180° bend or using 3M tape to pull. Electroplated products with poor adhesion will fail quickly during use.
- Solderability Test: Immerse the terminal in a 235°C solder bath for 5 seconds, then remove it and observe whether the wetted area is ≥95%. For terminals requiring soldering, this is a key indicator.
- Appearance inspection: Examine the coating color under a microscope with at least 10x magnification to check for uniformity, scratches, foreign objects, or exposed base material. The appearance often reflects the stability of the electroplating process.
- Salt Spray Test: Place the sample in a 5% salt spray chamber (35°C) to test corrosion resistance. Generally, it is required that no red or green rust appears within 24 to 48 hours.
- Packaging Inspection: Verify the product orientation, quantity, and label information for accuracy, and ensure that the internal and external labels are consistent to guarantee error-free shipment.
4.Factors Affecting Terminal Plating Costs
Terminal plating does not have a fixed standard unit price. Industry billing is mainly calculated based on plating thickness, plating material, product specifications, process complexity, environmental protection level, and order quantity.
a. Pricing Gradient of Coating Materials
Gold plating has the highest electroplating cost, with a unit price far exceeding that of tin or nickel plating;
Nickel base plating process has a moderate cost;
Conventional bright tin plating and matte tin plating have the lowest costs and are the preferred choices for mass production in terms of cost-effectiveness.
b.Coating thickness determines the cost
The thicker the coating, the stronger the corrosion resistance and wear resistance. Electroplating consumables and labor hours increase accordingly, leading to higher processing costs. Industrial terminals customize coating thickness according to usage standards, and the higher the thickness specification, the higher the quotation.
c.Product Specifications and Manufacturing Complexity
Miniature precision terminals and special-shaped terminals are difficult to plate accurately, have higher wastage, and incur costs higher than conventional through-hole and plug-in terminals; large-scale standardized mass production has a lower unit price, while small-batch custom processing results in higher prices.
d.Environmental Protection and Industry Certification Standards
Compliant with RoHS environmental protection standards, certified for automotive and military grades, with stricter chemical solutions and process controls, higher compliance costs, and plating fees higher than those for standard civilian-grade plating.
Although small, terminals are bridges connecting the world. From degreasing and pickling to selective electroplating, followed by coating thickness testing, adhesion inspection, and salt spray testing—every single process contributes to ensuring reliability.
Deke Electric has always firmly believed that quality comes from attention to detail, and reliability arises from professionalism. We have been deeply engaged in the terminal connector field for many years, equipped with fully automated continuous electroplating production lines, precision testing equipment, and a strict quality control system, dedicated to providing every customer with highly reliable connector electroplating solutions.
From the surface of a single terminal, one can glimpse the future of an entire device. Choosing Deke Electric is choosing stability and trust.
Guangdong DEKE Electric Co., Ltd.
Specializing in R&D and Manufacturing of Connectors & Terminals · High-Tech Enterprise · Pioneer in Domestic Substitution
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