What is the gold used in PCB manufacturing?

Businesses and consumers rely on electronic devices for almost every aspect of their daily lives.Cars are full of printed circuit board (PCB) for everything from lighting and entertainment to sensors that control the behavior of critical mechanical functions. Computers, tablets, smartphones and even many toys that children enjoy use electronic components and PCB for their complex functions.

Today’s PCB designers face the challenge of creating reliable boards that perform increasingly complex functions while controlling costs and reducing size. This is especially important in smartphones, drones and other applications, where weight is an important consideration in PCB characteristics.

Gold is an important element in PCB design, and keep an eye on the “fingers” on most PCB displays, including metal contacts made of gold. These fingers are usually multilayered metal and may include a material coated with a final layer of gold, such as tin, lead, cobalt or nickel. These gold contacts are critical to the function of the resulting PCB, establishing a connection with the product containing the board.

Why gold?

The attribute gold color makes it an excellent choice for PCB manufacturing. Gold-plated edge connectors provide a consistent surface finish for applications that undergo high wear, such as plate insertion edge points. The hardened gold surface has a stable surface that resists wear caused by this repeated activity.

By its very nature, gold is well suited to electronic applications:

It is easy to form and operate on connectors, wires and relay contacts

Gold conducts electricity very efficiently (an obvious requirement for PCB applications)

It can carry a small amount of current, which is crucial for today’s electronics.

Other metals can be alloyed with gold, such as nickel or cobalt

It does not discolor or corrode, making it a reliable connection medium

Melting and recycling gold is a relatively simple process

Only silver and copper provide higher electrical conductivity, but each is prone to corrosion, creating current resistance

Even thin gold applications provide reliable and stable contacts with low resistance

Gold connection can withstand high temperature

Thickness variation NIS can be used to meet the requirements of specific applications

Almost every electronic device contains some level of gold, including TVS, smartphones, computers, GPS devices, and even wearable technology. Computers are a natural application for PCBS containing gold and other gold elements, because of the need for reliable, high-speed transmission of digital signals that are better suited to gold than any other metal.

Gold is unmatched for applications including low voltage and low resistance requirements, making it an ideal choice for PCB contacts and other electronic applications. The use of gold in electronic equipment now far exceeds the consumption of precious metals in jewelry.

Another contribution gold has made to technology is the aerospace industry. Due to the high life expectancy and reliability of gold connections and PCBS integrated into spacecraft and satellites, gold was the natural choice for critical components.

Other matters needing attention in PCB

Of course, there are drawbacks to using gold in PCBS:

Price – Gold is a precious metal with limited resources, making it an expensive material used in millions of electronic devices.

Resource loss – one example is the use of gold in modern devices such as smartphones. Most smartphones are not recycled, and carelessly discarded can permanently lose a small amount of gold. Although the amount is small, the amount of waste equipment is large and can produce a considerable amount of unrecycled gold.

Self-coating may be prone to wear and smear under repeated or high pressure mounting/sliding conditions. This makes it most efficient to use harder materials for applications on compatible substrates. Another consideration for PCB use is to combine gold with another metal, such as nickel or cobalt, to form an alloy called “hard gold”.

The U.S. Environmental Protection Agency (EPA) reports that e-waste is growing faster than almost any other waste commodity. This includes not only the loss of gold, but also other precious metals and possibly toxic substances.

PCB manufacturers must carefully weigh the use of gold in PCB manufacturing: applying too thin a layer of metal can degrade or destabilize the board. Using extra thickness becomes wasteful and expensive to manufacture.

Currently, PCB manufacturers have very limited options or alternatives to live up to the capabilities and inherent properties of gold or gold alloys. Even with its high value, this precious metal is undoubtedly the material of choice for PCB construction.