As urbanization propels the development of self-driving technology and broader implementation of advanced driver assistance systems (ADAS), automotive OEMs and tiers are actively seeking high-performance materials that can optimize the capabilities of today’s higher-frequency (>75 GHz), millimeter-wave (mmWave) radar units. To help meet this need, SABIC is launching two new materials, LNP? THERMOCOMP? WFC06I and WFC06IXP compounds, developed for the front and back enclosure covers (respectively) of next-generation radar units. The new glass fiber-reinforced polybutylene terephthalate (PBT) grades offer a very low dissipation factor (Df) and dielectric constant (Dk) to help support the transmission of higher-frequency radar signals. They also feature super-low warpage that allows designers to potentially create new, thinner covers that improve signal transmission. Furthermore, these new SABIC products can contribute to efficient radar unit assembly by supporting high-speed, high-precision laser welding. In fact, LNP THERMOCOMP WFC06I compound provides excellent laser transmission performance among PBT materials currently available.

“Advancements in ADAS are accelerating rapidly as the automotive industry develops new vehicle technologies aimed at alleviating traffic congestion and improving safety in expanding urban areas,” said Joshua Chiaw, Director, Business Management, LNP & NORYL, Specialties, SABIC. “SABIC is aggressively developing new materials to help ADAS designers achieve goals related to size and weight reduction, signal transmission accuracy and reliability improvements, and seamless integration with the vehicle. We work closely with companies at all levels of the ADAS value chain to understand fast-changing and demanding requirements and deliver tailored, high-performance material solutions that address them.”

IMPROVING RADAR IMAGE RESOLUTION 

Many ADAS designers are adopting higher frequency mmWave radar technology because its improved image resolution and greater range can enable safer driving under a variety of conditions. However, frequencies in the 76 – 81 GHz band present greater transmission challenges compared to lower frequencies. To improve wave transmission, radar covers require very low Df and Dk, thinner walls and a simplified design without support structures. Incumbent glass-filled PBT materials typically do not meet these transmission optimization requirements; for example, they have a Df performance that is greater than 0.01. Also, as semi-crystalline polymers, they have a high tendency to warp when used in thin-wall parts without support structures, potentially leading to part failure during assembly, transport and use.  

SABIC’s new LNP THERMOCOMP compounds surpass incumbent PBT compounds in Df/Dk performance and warpage control and can reduce attenuation of electro-magnetic waves passing through the radar covers to help improve image resolution and range. They also enhance transmission and minimize side cones of the signal beam for improved image quality. In addition, the new LNP THERMOCOMP compounds provide higher ductility for improved impact resistance, and equivalent moisture and chemical resistance vs. incumbent PBT materials. 

FACILITATING LASER WELDING 

Laser welding is a fast and highly efficient automotive process that can accelerate throughput. Laser welding of plastic components offers advantages including the ability to produce miniaturized and highly intricate parts and eliminate consumables such as adhesives and fasteners. Precise, strong welds can protect sensitive electronics against dust and moisture. 

SABIC’s LNP THERMOCOMP WFC06I compound for radar front covers features a laser transmission rate of over 60 percent – 20 percent higher than the nearest competitor’s. Customers can use its wide laser window and low laser power to potentially increase yield rates. The other new grade – LNP THERMOCOMP WFC06IXP compound – acts as the absorbing layer for laser welding. 

“Reaching the full potential of automotive radar for assisted and autonomous driving requires improvements in design, performance and production efficiency,” said Jenny Wang, Director, Formulation & Application, APAC, Specialties, SABIC. “SABIC continues to break new ground in material science with the goal of solving our customers’ challenges in optimizing ADAS designs. Our new glass-filled PBT compounds contribute by supporting the adoption of new technologies like mmWave radar with enhanced features.”