John Timmerman, Ph.D.
Chanhassen, MN, USA
Chanhassen, MN, USA
Irvine, CA, USA
Products that manage thermal and electromagnetic challenges individually in electronics are well established in the current marketplace, but a need has emerged for materials and solutions that combine these two functionalities. In many new products and designs multiple heat and signal generating components cannot be isolated from each other using traditional means. In these applications a material that transfers heat and absorbs electromagnetic energy can be used to improve signal integrity, prevent crosstalk, and manage operating temperatures. These hybrid materials have various compositions and forms, which range from thin sheets to soft pads to reactive or non-reactive liquid materials.
The mechanical, thermal, electrical, and magnetic properties of these materials depend on their materials of construction as well as the macro and microscopic organization of the components involved. Many test methods exist to measure the thermal and electromagnetic properties of a material both in an application and as fundamental material properties. This paper will expand on these topics in more detail as well as discussing existing and future trends in thermal and electromagnetic materials development.
It was shown that through the right combination of matrix and fillers materials could be formulated to conduct heat and absorb electromagnetic energy in the 1-10GHz range. Increasing material thickness and magnetic loss tangent both significantly improved the amount of absorption for a given material. The material permeability was shown to affect performance through its variation with frequency. Application testing showed the utility of hybrid thermal/EMI absorbing materials. Overall, these materials will continue to find more use in electronics as devices shrink, speeds increase, and component densities grow.
Initially Published in the SMTA Proceedings