Why I made myself a business card the size of a postage stamp (out of Liquid Crystal Polymer) that requires a 40X microscope to see the details

by Mike McCulley / May 31, 2019

Imagine a computer with the same functionality that your powerful gaming laptop has today, but it is the size of the palm of your hand and flexible enough to shove in your front pocket. This type of form factor is now possible with the introduction of a revolutionary new processing method for making circuit boards using liquid crystal polymer (LCP).

Liquid crystal polymer technology is the future of circuit design and manufacturing for high performance electronics. Benchmark is commercializing new LCP manufacturing methods for the fabrication of microelectronic circuits. Advances in LCP manufacturing will lead to a significant reduction in size, weight and power (SWaP) while supporting new electronics designs in military, commercial and medical markets that demand performance from 10 GHz to 110 GHz. 

Benchmark_AD-Article-graphic-03Our unique approach for manufacturing LCP for circuits leverages conventional processes, but overcomes the historical challenges of working with LCP. We are introducing the multiple benefits of LCP for next generation electronics. Benefits include a low, stable, dielectric constant (Dk), a low, stable loss tangent (TanD), a coefficient of thermal expansion (CTE) well matched to other electronic materials like copper, great mechanical flexibility and near-hermetic characteristics with low moisture absorption.

In order to demonstrate some properties of our LCP manufacturing process, I decided to make some business cards out of LCP for an upcoming tradeshow, the International Microwave Symposium (IMS) 2019. Being an engineer myself, I knew senior engineers at the show would be more likely to believe our claims if they could see them with their own eyes. Therefore, in partnership with product marketing, I designed a postage stamp sized business card out of LCP. I kept it small to get as many business cards from one panel of substrate material as possible.

The business card is made using LCP substrate. The LCP substrate used here is 2 mil thick; LCP comes with copper on both sides, which is then etched to get just the thin sheet of LCP.

The idea of the business cards was to make a real example to highlight Benchmark’s unique technology. The card has ten each of 1 mil (25.4 microns) thick lines with 1 mil of spacing between them. There are two RF resonators on the cards. A resonator is a device that exhibits resonant behavior; meaning it naturally oscillates at some frequencies with greater amplitudes than the others do. Resonators are used either to generate waves of specific frequencies or to select specific frequencies from a signal. The resonators on the business cards are not designed for any particular frequency; we just added them to prove what our technology can do. The road map for the technology is to be able to make lines and spacing less than 0.7 mils (10-12 microns).

The LCP business cards will be available at IMS, and the engineers will be able to see the detail with scopes we have set up. We will tell them that they should bring the samples home and show their co-workers under their own scopes. I am already planning business card sample 2.0 with even more features!

At the end of the day for me, it is all about educating our field on the amazing benefits of designing electronics with new high performance materials. LCP enables next generation size, weight and power (SWaP) reduction for a wide range of electronics, IoT sensors and edge devices. The benefits are many: conveniently bury bare dies, components and circuit lines inside layers of LCP substrate and create a significant decrease in the overall packaging footprint, while maintaining a high electronic density. I feel privileged to push the limits of technology at Benchmark’s RF and High Speed Design Center in Phoenix, AZ. Reach out if you would like to learn more about what LCP can do for your project. I would be glad to help.

RF & High Speed Circuit Design RF & High Speed Technology

about the author

Mike McCulley

Mike McCulley is a senior mechanical engineer at Benchmark Lark Technology. Mike is involved in aerospace and defense projects, as well as research and development in thermal management solutions and miniaturization. Mike has a diverse background in engineering design and manufacturing. During his 30-year career, he has held positions from Chief Technical Officer at Tangible Layer and Director of Engineering for White Sands Engineering, to Senior Mechanical Engineer at Google. Mike got his start in engineering at a young age working with his father, the owner of a precision sheet metal and machine shop.