Heavy Copper PCBs: Bridging the Gap Between Design and Fabrication, Part 1
April 1, 2024 | Yash Sutariya, Saturn Electronics ServicesEstimated reading time: 1 minute

They call me Sparky. This is due to my talent for getting shocked by a variety of voltages and because I cannot seem to keep my hands out of power control cabinets. While I do not have the time to throw the knife switch to the off position, that doesn’t stop me from sticking screwdrivers into the fuse boxes. In all honesty, I’m lucky to be alive. Fortunately, I also have a talent for building high-voltage heavy copper circuit boards. Since this is where I spend most of my time, I can guide you through some potential design for manufacturability (DFM) hazards you may encounter with heavy copper design.
I have always perceived the term “heavy copper” as a printed circuit board with layers containing at least three ounces of finished copper. Recently, I’ve noticed a peculiar trend. We see monikers being used to describe higher copper weights (think 10-ounce, 20-ounce) that are seemingly pulled right out of a ’90s-era Mountain Dew commercial: “extreme copper” or “super copper.” I’m trying to coin the term “stupid crazy copper,” but somehow, I don’t think it will stick.
These are all fabricated descriptions to highlight achievements in building PCBs beyond our industry’s standards. There is no standard definition for heavy copper from IPC, but that doesn’t mean we can’t have fun designing and building these beasts of the PCB world.
No matter what you call them or how you define them, we can all agree on why we use them. Heavy copper boards increase current carrying capacity and decrease circuit failures by reducing thermal resistance. To reduce layer count, some will contain more copper on the inner layers than the outer; moreover, some will even have different amounts of copper on the same layer. They can also function as a heat sink thanks to plated vias and their capacity to carry a higher current and heat through the board. Above all, they have eliminated the need for those complex wired buss configurations that C-3PO was forced to endure.
To read the rest of this article, which appeared in the March 2024 issue of Design07 Magazine, click here.
Suggested Items
Designers Notebook: Addressing Future Challenges for Designers
02/06/2025 | Vern Solberg -- Column: Designer's NotebookThe printed circuit board is and will probably continue to be the base platform for most electronics. With the proliferation of new generations of high I/O, fine-pitch surface mount semiconductor package variations, circuit interconnect is an insignificant factor. Circuit board designers continually face challenges such as component quantity and complexity, limited surface area, and meeting the circuit board’s cost target. The printed circuit design engineer’s prominent position demands the development of efficiently manufacturable products that perform without compromise.
DesignCon 2025, Day 2: It’s All About AI
01/30/2025 | Marcy LaRont, I-Connect007It’s hard to get away from the topic of artificial intelligence, but why would you? It’s everywhere and in everything, and my time attending presentations about AI at DesignCon 2025 was well worth it. The conference’s agenda featured engaging presentations and discussions focused on the technological advancements in AI, big data centers, and memory innovations, emphasizing the critical relationship between processors and circuit boards.
Beyond Design: Electro-optical Circuit Boards
01/22/2025 | Barry Olney -- Column: Beyond DesignPredicting the role of PCB designers in 10 years is a challenge. If only I had a crystal ball. However, we know that as technology progresses, the limitations of copper PCBs are increasingly apparent, particularly regarding speed, bandwidth, and signal integrity. Innovations such as optical interconnects and photonic integrated circuits are setting the stage for the next generation of PCBs, delivering higher performance and efficiency. The future of PCB design will probably incorporate these new technologies to address the challenges of traditional copper-based designs.
Designers Notebook: Impact of Advanced Semiconductor Packaging on PCB Stackup
01/07/2025 | Vern Solberg -- Column: Designer's NotebookTo accommodate new generations of high I/O semiconductor packaging, printed circuit board fabrication technology has had to undergo significant changes in both the process methods and the criteria for base material selection and construction sequence (stackup). Many of the new high-function multi-core semiconductor package families require more terminals than their predecessors, requiring a significantly narrower terminal pitch. Interconnecting these very fine-pitch, high I/O semiconductors to the PCB is made possible by an intermediate element referred to as an interposer.
BOOK EXCERPT: The Printed Circuit Designer’s Guide to... High Performance Materials, Chapter 4
01/02/2025 | I-Connect007In Chapter 4, Michael Gay discusses the two main types of copper foil used for PCB boards today: electrodeposited (ED) foil and rolled annealed (RA) foil. He also explains the pros and cons of each, and provides an update of the latest innovations in copper foil technology.