The electronics and semiconductor industries rely heavily on advanced materials to ensure the efficiency, reliability, and longevity of components. Among these, gold-plated fine wires stand out for their exceptional electrical conductivity, corrosion resistance, and durability. While other materials such as silver, copper, and palladium are occasionally employed for specific purposes, gold remains the material of choice for high-performance applications. LUMA is a trusted supplier of a wide range of fine wires designed to meet the exacting demands of this sector, offering solutions that combine precision engineering with advanced material science.
Gold plating on wires provides a conductive and corrosion-resistant surface layer, making these wires ideal for electrical connectors, printed circuit boards (PCBs), and other critical components. In addition to improving solderability and weldability, the gold coating ensures long-term reliability, particularly in environments prone to oxidation or harsh conditions.
When copper is used as the core material, there is a risk of copper atoms diffusing through the gold coating, leading to tarnishing and the formation of oxides or sulfides. To address this, LUMA provides nickel-gold plated wires, where a nickel strike layer acts as a diffusion barrier, enhancing wear resistance and preserving surface integrity.
These qualities make fine wires in electronics essential for connectors, PCBs, and high-performance components.
Ulrik Palmqvist, Ph.D.
You are welcome to contact me when you need professional assistance
Wire bonding is a critical interconnect technology used to create electrical pathways for power and signal transmission. Traditionally, solid gold wires dominated this field, but due to the rising cost of gold, gold-plated copper wires have emerged as a viable alternative.
The gold layer protects the copper core from corrosion while maintaining excellent conductivity. In some cases, silver wires are employed as the base material, with a nickel strike layer added to improve gold adhesion. LUMA’s expertise in producing high-quality gold-plated wires supports advancements in this essential technology, which is integral to semiconductor packaging and microelectronic devices.
The control modules are the second most expensive component, for instance in an electric vehicle, besides the battery itself. This is where high currents are reduced using special semiconductors.
A transistor has two contact areas on its surface. One is for switching, the gate pad, and then there is the source current contact, the source pad. A lot of current flows out of the source pad—many dozens of amperes.
A chip measuring 5 × 5 millimeters can easily handle 90 or 100 amperes. These then have to be routed from the source pad to the leadframe through a small group of wires. That is generally done with just a single wire, sometimes two—very thin because the contact areas are far too small. You can’t simply solder something onto them. If even just one gate is contacted incorrectly, everything is scrap. That is why a high-quality wire loop will certainly continue to exist.
Instead of a wire loop braided material / structures might be an option to be investigated. They might be easier to implement.
Power transistors differ from the multitude of other transistors used for RF and graphics/PC applications. Compared to those, power transistors are enormous. These 5 × 5 mm chips would even fit on a small transistor. On 5 × 5 mm you could fit an entire laptop CPU with 100 million transistors. But that device doesn’t have to carry large currents. Those operate in the nanoampere range, and with that you can’t perform energy-intensive work—there are no hundreds or even thousands of amperes being generated, which is what power electronics requires.
Chips are becoming ever smaller while carrying more and more amperes per unit area, so on an ever-shrinking surface more and somewhat stronger wires are needed. They have to be welded / bonded with high ultrasonic energy. In the process, the chip can be damaged very easily. You’re always working against an optimum that lies just short of destroying the chip. That’s why the requirements for such wires are extremely high.
This is an argument in favor of Luma´s robust Tungsten or Molybdenum wires as base wire materials, with gold plating added for the bonding process. Tolerances are very tight. Luma has the Know How and vast experience to guarantee consistent quality and functionality in the application.
There are different techniques with very different qualities.
Bonding can be positioned very precisely, down to the nanometer range. State of the art machines can do it smoothly.
The bond wires sit on Microchips and connect the hot transistor to the leadframe in a loop. The leadframe consists of the mechanical carrier, the chip attach area (die pad), and the terminal leads. The chip is glued in place. The bond wires connect the chip pads to the leads. After bonding, the whole assembly is encapsulated (packaging). The loop is there so that thermal expansion can be compensated in the form of spring-like movement.
A cheaper and less quality orientated technique is soldering of a stiff, stamped copper bridge instead, between the transistor and the leadframe. This lasts only a fraction of the time compared to bond wires because it has no elasticity.
Another disadvantage with soldering: You first have to position the object. And of course you have to apply solder, usually by dispensing. After that, it has to be washed in order to remove organic residues. You don’t have this with wire bonding. Wire bonding is dry and clean, and there’s no need for washing afterward.
Surface treatments are tested designed to facilitate the welding process or even achieve better electrical conductivity than copper. Luma as a specialist for coating technology on ultra fine wires can assist with testing different kinds of plating materials.
“Fuzz buttons” are discrete signal contacts fabricated from gold-plated fine wires, typically gold-plated molybdenum or beryllium copper. These contacts are formed into dense cylindrical structures and are valued for their high conductivity, mechanical strength, and oxidation resistance.
Fuzz buttons are widely used in applications requiring reliable performance under extreme conditions, including aerospace, military systems, and commercial electronics. Their excellent resistance to vibration, shock, and temperature variations makes them indispensable in satellite and space technology. For instance, gold-plated tungsten wires are preferred in environments subjected to high currents or extreme thermal fluctuations due to their superior structural stability.
Elastomeric connectors are versatile components designed for shock absorption, vibration resistance, and high-reliability connections in challenging environments. These connectors consist of alternating layers of insulating material and conductive wires, often gold-plated copper, to ensure consistent performance.
Gold plating is further optimized by adding a nickel strike layer to the core wire before the gold coating, enhancing durability and resistance to corrosion. Elastomeric connectors are commonly found in mobile phones, radar systems, memory cards, and display technologies. Their small size and high reliability align with the growing trend toward miniaturization in microelectronics.
Integrated circuit testing involves using probe needles or pins to evaluate the connections on assembled circuit boards. Tungsten and tungsten-rhenium wires, either gold-plated or uncoated, are ideal for this application due to their strength, conductivity, and resistance to oxidation.
These wires are used to fabricate probe needles for wafer sort testing, LCD and LED probe applications, and nanotechnology, as well as medical electrodes and other industrial uses. LUMA ensures the wires used in probes meet stringent quality standards, offering clean or polished surfaces, multi-layer coatings, and enhanced straightness to minimize material flaws.
The accuracy and longevity of probe needles are critical; their sharp tips must maintain precision without deforming or cracking under repeated use. Tungsten-based probe needles are renowned for their low and stable contact resistance, non-oxidizing properties, and minimal pad damage, making them an essential tool in modern electronics testing
LUMA’s extensive expertise in producing fine wires for the electronics and semiconductor industries is rooted in decades of innovation and a commitment to quality. By leveraging advanced plating techniques, precision manufacturing, and a deep understanding of material science, LUMA continues to support technological advancements across a broad spectrum of applications.
From fuzz buttons and elastomeric connectors to wire bonding and integrated circuit testing, LUMA fine wires remain at the forefront of modern electronics, enabling high performance, reliability, and durability in increasingly demanding environments.
Looking for precision-engineered solutions in electronics? Luma Wire Tech supplies fine wires in electronics trusted worldwide for semiconductors, connectors, and testing applications.
All our wires are manufactured in Sweden under strict ESG principles and in full compliance with international quality standards such as ISO
. This ensures that every product we deliver meets the highest levels of safety, traceability, and performance required by the electronics and semiconductor industries.
Contact us today to discuss your project requirements and learn how our fine wires can bring unmatched reliability to your electronic applications.
Why are gold-plated fine wires used in electronics?
Because they provide superior conductivity, corrosion resistance, and long-term reliability.
What are common applications of fine wires in semiconductors?
They are used in fuzz buttons, elastomeric connectors, wire bonding, and probe needles for IC testing.
Can Luma provide custom wire solutions?
Yes, Luma offers wires from 5 to 150 microns with tailored plating and finishes for electronics and semiconductor industries.
Gold-plated, polished and clean metal wires for demanding technical applications.
Our team support demanding wire applications.