Uploaded June 2026 | Updated September 2026, 2 weeks ago
Take your RF microstrip designs from schematic to fabricated boards with Altium Develop, the cloud platform that unites design, sourcing, and manufacturing in real time: altium.com/develop?utm_source=youtube&utm_medium=video&utm_campaign=altium-academy-shorts&utm_content=why-remove-solder-mask-on-rf-microstrip-lines-pcb-design-tip
Ever wondered why PCB designers pull the solder mask off RF microstrip lines? In this quick design tip, we answer a viewer question about opening the solder mask over microstrip antenna feed lines and explain the signal integrity reasoning behind it. The key is loss tangent: solder mask has a loss tangent around 0.025, roughly ten times higher than the 0.002 typical of low-loss RF substrate materials. When you route a microstrip line on a high-performance RF laminate and then coat it with solder mask, you're effectively layering a lossy dielectric on top of a low-loss one, undoing the advantage of the RF material.
Using real insertion loss data, we walk through what happens to a bare copper interconnect versus a mask-covered trace as frequency climbs. At around 1 GHz the difference is negligible, but once you reach Wi-Fi frequencies the added loss becomes noticeable, and above 10 GHz it becomes significant. That's why high-frequency RF microstrip routing in the gigahertz range is typically left mask-open. If you design RF boards, antennas, or high-speed interconnects, this tip will help you avoid unnecessary insertion loss and keep your high-frequency signals clean.
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The Altium Academy is an online experience created to bring modern education to PCB Designers and Engineers all across the world. Here you can access a vast library of free training and educational content covering everything from basic design to advanced principles and step-by-step walkthroughs. Join industry legends as they share their career knowledge, review real-life design projects, or learn how to leverage one of Altium's leading design tools. No matter your level of experience, the Altium Academy can help you become a better Designer and Engineer!
About Altium LLC
Altium LLC (ASX:ALU), a global software company based in San Diego, California, is accelerating the pace of innovation through electronics. From individual inventors to multinational corporations, more PCB designers and engineers choose Altium software to design and realize electronics-based products.
#RFDesign #PCBDesign #Altium
Take your RF microstrip designs from schematic to fabricated boards with Altium Develop, the cloud platform that unites design, sourcing, and manufacturing in real time: altium.com/develop?utm_source=youtube&utm_medium=video&utm_campaign=altium-academy-shorts&utm_content=why-remove-solder-mask-on-rf-microstrip-lines-pcb-design-tip
Ever wondered why PCB designers pull the solder mask off RF microstrip lines? In this quick design tip, we answer a viewer question about opening the solder mask over microstrip antenna feed lines and explain the signal integrity reasoning behind it. The key is loss tangent: solder mask has a loss tangent around 0.025, roughly ten times higher than the 0.002 typical of low-loss RF substrate materials. When you route a microstrip line on a high-performance RF laminate and then coat it with solder mask, you're effectively layering a lossy dielectric on top of a low-loss one, undoing the advantage of the RF material.
Using real insertion loss data, we walk through what happens to a bare copper interconnect versus a mask-covered trace as frequency climbs. At around 1 GHz the difference is negligible, but once you reach Wi-Fi frequencies the added loss becomes noticeable, and above 10 GHz it becomes significant. That's why high-frequency RF microstrip routing in the gigahertz range is typically left mask-open. If you design RF boards, antennas, or high-speed interconnects, this tip will help you avoid unnecessary insertion loss and keep your high-frequency signals clean.
💡 Stay Connected:
Don't forget to like, comment, and subscribe for more in-depth tutorials and tips from @AltiumAcademy Share your thoughts and questions in the comments below!
👉 Subscribe for more: youtube.com/@AltiumAcademy?sub_confirmation=1
Don't forget to follow us on social to stay up-to-date on the latest Altium Academy content.
👉 Follow Altium on TikTok: tiktok.com/@altiumdesigner
👉 Follow Altium on Twitter: twitter.com/altium
👉 Follow Altium on Linkedin: linkedin.com/company/altium
👉 Follow Altium on Facebook: facebook.com/AltiumOfficial
The Altium Academy is an online experience created to bring modern education to PCB Designers and Engineers all across the world. Here you can access a vast library of free training and educational content covering everything from basic design to advanced principles and step-by-step walkthroughs. Join industry legends as they share their career knowledge, review real-life design projects, or learn how to leverage one of Altium's leading design tools. No matter your level of experience, the Altium Academy can help you become a better Designer and Engineer!
About Altium LLC
Altium LLC (ASX:ALU), a global software company based in San Diego, California, is accelerating the pace of innovation through electronics. From individual inventors to multinational corporations, more PCB designers and engineers choose Altium software to design and realize electronics-based products.
#RFDesign #PCBDesign #Altium
