Automotive Engineering - March 2025 - 25

ADAS SENSORS FEATURE
Advanced silicones
for ADAS
in light
vehicles
Using decades of experience in automotive electronics,
Dow's R&D scientists provide a broad portfolio of
innovative, proven silicone materials developed for ADAS applications.
Material solutions for thermal management, protection and assembly.
by Joseph Sootsman and Lu Zou
T
oday's ADAS designers are adding more electronic
components and redundant computing
systems to printed circuit boards (PCBs). These
heat-generating electronic assemblies are installed
in enclosures that provide environmental protection,
but the high heat generated by high-performance
computing systems can degrade ADAS performance
or cause device failure.
Not all thermal management materials can withstand
temperatures up to 200 C (392 F), and most do
not retain their flexibility at elevated temperatures.
This creates a problem when PCB components expand
and contract at different rates due to mismatches in
their coefficients of thermal expansion.
In addition to high temperature resistance and
thermal stability, automotive engineers need materials
that resist shock and vibration. The enclosures
that house ADAS electronics components can be
sealed to exclude water, however additional PCBlevel
protection with a conformal coating can be
used to prevent moisture or debris from impacting
device performance. With the increasing number of
electronic components and high-frequency devices
like radar in light vehicles, shielding against electromagnetic
interference (EMI) is also needed.
AUTOMOTIVE ENGINEERING
Furthermore, because the number of ADAS components continues
to increase, the fast and efficient assembly of these modules presents
challenges. Engineers need materials that support automated dispensing
and rapid curing. Increased environmental sustainability initiatives
are also driving the demand for a reduction in the amount of
energy that heat curing requires. Automakers are pushing engineers
to use materials that cure at room temperature or with ultraviolet
(UV) light, but ADAS designers still need solutions for protection and
assembly that are compatible with a variety of PCB materials, provide
chemical resistance, and are cost-effective to apply.
Advanced silicones solve multiple challenges
Advanced silicones can meet these challenges and offer important
advantages over organic materials. For example, advanced silicones
can withstand temperatures up to 200 C. By contrast, epoxies are
prone to cracking from thermal stresses. In addition, silicones retain
their flexibility even when fillers that impart thermal or electrical conductivity
are added. With their low modulus, silicones can relieve
stresses that result when different PCB materials, such as metals and
plastics, expand and contract at varying rates.
Advanced silicones also resist the shock and vibration that is common
in automotive environments. They also absorb significantly less
water for long-term moisture and water resistance, can be formulated
to resist the spread of fire and can cure at room temperature or
March 2025 25
DOW
Automotive Engineering - March 2025

Table of Contents for the Digital Edition of Automotive Engineering - March 2025
