FAQ - Microwave PCB Materials


Reading time ( words)

The landscape of specialty materials changes so quickly that it can be hard for product developers to keep up. As a result, PCB designers are inundated with data about microwave PCB materials. But very often, it’s difficult to find useful information regarding these specialty substrates. So, this month, we present some of the most frequently asked questions about microwave materials encountered at Rogers.

Q:  At what frequency is it necessary to transition from FR-4 types of materials to high-frequency circuit materials?

A:  This is a challenging question to answer because different technologies can tolerate more or less performance from a laminate. I’ll give a few examples and basic guidelines.

Semiconductor technology has developed enhanced signal processing to the point where a FR-4 material could be used at higher speeds and frequencies than was once thought possible. In most cases where high-speed digital applications reach 10 Gbps or more, you will need to use a high-frequency laminate. There are exceptions, and in some cases a lower data rate PCB will also demand a high-frequency laminate.

High-frequency RF circuits, which are less concerned with insertion loss, could use FR-4 in some of these applications. However, high-frequency laminates offer more than just low loss; they provide very well-controlled dielectric constant. In many RF applications, the control of dielectric constant for the material can be as critical as substrate thickness control. As a general statement, FR-4 materials are typically not used above 3 GHz in RF applications due to insertion loss concerns. However, when dielectric constant control is a critical concern, high-frequency materials should be used instead of FR-4 materials.

Read the full column here.


Editor's Note: This column originally appeared in the February 2014 issue of The PCB Design Magazine.

Share




Suggested Items

Producing Diverse Designs in Concert With Manufacturing

06/16/2022 | Scott Miller, FreedomCAD Services
There is a new acronym bubbling up in the design world: DWM, which stands for “design with manufacturing.” Why is this different than design for manufacturing, or DFM? With DWM, the emphasis is on integration between the design team and the manufacturers during the design process. DWM is much more than that. We are tasked with producing designs that meet various technical requirements, yet are cost-effective and manufacturable. We provide this service to hundreds of customers who have varying degrees of processes, tools, and manufacturing partners. Given this diversity, we have recognized the importance of designing with manufacturing to achieve the product development goals of manufacturability and technical excellence.

Book Excerpt: 'The Printed Circuit Designer’s Guide to… High Performance Materials,' Chapter 2

06/03/2022 | I-Connect007 Editorial Team
Chapter 2 of 'The Printed Circuit Designer’s Guide to… High Performance Materials' explores the varieties of woven glass fabrics and their components, and why spread glass is in such high demand for high-speed digital PCB designs. Download this book for a clearer picture of what to know when selecting which material that is most desirable for upcoming products, and obtain a solid knowledge base for making material selection decisions.

Additive Manufacturing Requires Additive Design Techniques

05/09/2022 | Luca Gautero, SUSS MicroTec
Although I am not a designer by trade, I want to share my thoughts on what additive manufacturing means for designers, especially how it relates to solder mask. In this article, you will learn what topics I feel are the most important to address.



Copyright © 2022 I-Connect007. All rights reserved.