LANXESS develops concept for radar sensors with integrated thermal management

LANXESS has developed a new concept for radar sensors with integrated thermal management that will benefit autonomous driving. 360-degree radar sensors are an essential component of, for example, distance control, lane change monitoring, collision avoidance and blind spot monitoring systems. 

The sensors have to be both dust- and waterproof and so are designed as fully enclosed systems. But this makes it difficult for heat to be effectively dissipated from the inside, which, in turn, can impair the performance of the electronics and durability of the sensors.

“This is why we developed a concept that allows heat to be dissipated by means of thermally conductive plastics in combination with metallic cooling elements,” said Gregor Jaschkewitz, Application Developer in the High Performance Materials (HPM) business unit at LANXESS. “The individual sensor components are assembled using integrated snap fits and hot rivets, a process that is much less costly and time-consuming than using screws.” 

For a radar sensor, this new concept from LANXESS involves the following individual components: a front cover (“radome”), radar absorber, PCB – including antennas – and back cover with an integrated cooling element.

The radome faces away from the vehicle and has to be made from a plastic offering a high degree of transmission for the radar waves. Polybutylene terephthalate (PBT) is well-suited due to its low dielectric constant (D_k) and loss factor (D_f).  

The back cover is manufactured in a plastic-metal compound (hybrid) technique with polyamide 6 and a metallic cooling element. This enables engineers to leverage the huge design freedom offered by the injection moulding process.

Importantly, the surface of the metallic cooling element can be over-moulded with thin areas of plastic.

Jaschkewitz added: “The heat generated on the electronic components of the PCB can be efficiently dissipated from the whole assembly through these plastic areas. This effect is supported by thermally conductive polyamide 6 from our Durethan BTC product range as injection molding material.”

Another benefit of the hybrid design is that the metallic cooling element shields the electronics inside the radar sensor against electromagnetic radiation.

The assembly can be sealed with O-rings or sealing lips created in a two-component injection moulding process.