-
- News
- Books
Featured Books
- design007 Magazine
Latest Issues
Current IssueShowing Some Constraint
A strong design constraint strategy carefully balances a wide range of electrical and manufacturing trade-offs. This month, we explore the key requirements, common challenges, and best practices behind building an effective constraint strategy.
All About That Route
Most designers favor manual routing, but today's interactive autorouters may be changing designers' minds by allowing users more direct control. In this issue, our expert contributors discuss a variety of manual and autorouting strategies.
Creating the Ideal Data Package
Why is it so difficult to create the ideal data package? Many of these simple errors can be alleviated by paying attention to detail—and knowing what issues to look out for. So, this month, our experts weigh in on the best practices for creating the ideal design data package for your design.
- Articles
- Columns
- Links
- Media kit
||| MENU - design007 Magazine
Book Excerpt: The Printed Circuit Designer’s Guide to... DFM Essentials, Ch. 1
October 25, 2024 | I-Connect007Estimated reading time: 1 minute

Excerpt from: The Printed Circuit Designer’s Guide to... DFM Essentials
By Anaya Vardya, American Standard Circuits / ASC Sunstone Circuits
Chapter 1: Materials
Standard Multilayer Materials
Most PCBs are manufactured using three basic materials: glass-reinforced epoxy laminate, prepreg, and copper foil. PCBs are constructed from three basic material types: copper foil, prepreg, and cores.
Copper foil: Sheets of copper foil are incorporated into the outer layer of the PCB, laminating it onto the prepreg to create the outer layers. Outer layers are generally constructed using ½-ounce copper or thicker depending on the design requirements. Internal layers are constructed with copper that is specified on the fabrication print. Half-ounce copper foil is commonly used for signal layers; 1 ounce for plane layers, and 2 ounce or greater for power planes where there is a high DC current. Other thicknesses may be used based on the design requirements.
Prepreg: This is a semi-cured glass resin material. The resin used for the FR-4 type materials is epoxy-based. There is no copper attached to this material.
Core: This is fully cured glass-resin material with copper laminated to both sides. This is typically used for internal layers. It is occasionally used for outer layers, but that is not a preferred construction method. A core is constructed from either one sheet of prepreg (single ply) or two or more sheets of prepreg, and two layers of copper foil. Single ply is considered the preferred core construction and has better dimensional stability.
High-frequency (RF/Microwave) Materials
High-frequency designs (1 GHz and up) require materials with closely controlled dielectric constants and dissipation factors. The FR-4 materials normally used for PCBs don’t have the desired controlled characteristics. The substrate materials used for high-frequency applications were originally based upon PTFE resin formulations that have the desired properties, i.e. dielectric constant (Dk) controlled to +/- 0.04 and dissipation factor (Df) to 0.0004. These values may vary somewhat depending on the material type and supplier. Today, there are a number of materials on the market that do not contain PTFE resin but still have controlled values that can be used for high-frequency applications.
Visit the I-Connect007 library to continue reading The Printed Circuit Designer’s Guide to... DFM Essentials.
Suggested Items
I-Connect007 Editor’s Choice: Five Must-Reads for the Week
07/18/2025 | Nolan Johnson, I-Connect007It may be the middle of the summer, but the news doesn’t quit, and there’s plenty to talk about this week, whether you’re talking technical or on a global scale. When I have to choose six items instead of my regular five, you know it’s good. I start by highlighting my interview with Martyn Gaudion on his latest book, share some concerning tariff news, follow that up with some promising (and not-so-promising) investments, and feature a paper from last January’s inaugural Pan-European Design Conference.
Elephantech Launches World’s Smallest-Class Copper Nanofiller
07/17/2025 | ElephantechJapanese deep-tech startup Elephantech has launched its cutting-edge 15 nm class copper nanofiller – the smallest class available globally. This breakthrough makes Elephantech one of the first companies in the world to provide such advanced material for commercial use.
Copper Price Surge Raises Alarms for Electronics
07/15/2025 | Global Electronics Association Advocacy and Government Relations TeamThe copper market is experiencing major turbulence in the wake of U.S. President Donald Trump’s announcement of a 50% tariff on imported copper effective Aug. 1. Recent news reports, including from the New York Times, sent U.S. copper futures soaring to record highs, climbing nearly 13% in a single day as manufacturers braced for supply shocks and surging costs.
I-Connect007 Editor’s Choice: Five Must-Reads for the Week
07/11/2025 | Andy Shaughnessy, Design007 MagazineThis week, we have quite a variety of news items and articles for you. News continues to stream out of Washington, D.C., with tariffs rearing their controversial head again. Because these tariffs are targeted at overseas copper manufacturers, this news has a direct effect on our industry.I-Connect007 Editor’s Choice: Five Must-Reads for the Week
Digital Twin Concept in Copper Electroplating Process Performance
07/11/2025 | Aga Franczak, Robrecht Belis, Elsyca N.V.PCB manufacturing involves transforming a design into a physical board while meeting specific requirements. Understanding these design specifications is crucial, as they directly impact the PCB's fabrication process, performance, and yield rate. One key design specification is copper thieving—the addition of “dummy” pads across the surface that are plated along with the features designed on the outer layers. The purpose of the process is to provide a uniform distribution of copper across the outer layers to make the plating current density and plating in the holes more uniform.