Why Is Copper Used in Printed Circuit Boards?

Printed circuit boards (PCBs) have become a staple in virtually all areas of modern technology. Everything from smartphones to 3D printers makes use of PCBs, and the prevalence of PCBs in daily life is only going to increase. Of all the components that make up PCBs, copper is one of the most important.

Copper’s unique properties make it the best choice for PCBs. Read this blog to learn more about the amazing properties of this metal and why it’s used in circuit boards.

Copper Is Highly Conductive

PCBs rely on electricity in order to perform their myriad functions. The titular circuits in these circuit boards are essentially pathways that channel electric charges from one location to another, and the pathways must be able to carry the charges efficiently. While dozens of substances can carry electric charges, copper is particularly conductive, so it has become the standard choice.

The reason for copper’s high level of conductivity is that it has only one valence electron, also known as a free electron. Such electrons can travel freely from one atom to another with very little resistance. Electrons are the fundamental particles that hold electrical charges, so free electrons are responsible for transferring electrical signals. Copper transfers these signals without losing electricity.

In fact, copper is the second-best conductor of electricity of all metals on earth, with only silver being more conductive. Plenty of other metals and alloys can be used in circuit boards, but copper’s high level of conductivity, combined with its other useful properties, makes it a great choice.

Copper Is Great for Electroplating

Electroplating is the process of creating a very thin layer of metal onto a section of the circuit board by treating the board and submersing it in a special liquid bath. This is an important process, and copper is an excellent metal to be used in electroplating. This property makes it incredibly useful, as not many metals can be electroplated as well as copper.

Copper Is Very Ductile

In addition to being a good choice for electroplating, the metals used in PCBs need to be ductile. When a metal is ductile, it can be drawn into a long, thin wire. Metals that aren’t ductile will break or snap instead of forming a wire. The thinner a wire is, the less space it takes up, which allows for a more compact PCB. Additionally, thin wires consume fewer resources, which reduces the cost of the PCB.

Copper is incredibly ductile. While other metals, such as gold, are even more ductile, these metals are prohibitively expensive. Due to copper’s high conductivity combined with its ductile properties, it’s the best choice for making high-quality, cost-effective wires.

Copper Pours Help PCBs Operate

A copper pour is a portion of the PCB that has been filled with copper. This will function as a ground plane, which is connected to the power supply ground terminal. It also serves as a return path for the current from different areas from the board. Copper pours are a common feature on PCBs because they help control the electrical signals traveling between different points on the PCB.

Copper is uniquely suited for this role. Not only is it malleable enough to be implemented and conductive enough to facilitate the transfer of electricity, but it also serves to regulate heat within the PCB. The copper pour is often etched with a cross-hatch pattern in order to prevent the PCB from warping.

Copper Is Relatively Low-Cost

Copper is far cheaper than the most conductive metal, silver — and gold, which is far more ductile than copper, is even more expensive. Some electronics do use silver and gold, but if some of these expensive materials can be replaced with low-cost copper, doing so will make the PCBs far more affordable.

What about cheaper metals? Aluminum, for example, is the fourth-most conductive metal, and it costs a fraction of what copper costs. However, aluminum isn’t nearly ductile enough to be used for effective wires, and copper is much better for electroplating. Such metals may seem like good options, but copper has other properties that make it worth the price.

Copper is one of the most important components of printed circuit boards, and for good reason. The balance of conductivity, ductility, and low cost allows it to serve a wide variety of functions within PCBs. Other metals have important roles within PCBs, but if you’re going to understand the workings of circuit boards, you need to understand why copper is so useful.

Streamline Circuits produces advanced printed circuit boards at competitive prices. We use advanced engineering to produce the best PCBs we can, and we work hard to keep the prices affordable so everyone can enjoy advanced PCB technology. Call us today to speak with an experienced member of our team about your needs, and let us help your business succeed.