Ceramic-based
electrical components for automotive applications have become exponentially
more sophisticated while their size continues to decrease.
Madison Avenue’s slick car ads often
highlight different driving conditions to showcase key selling points like
safety and audio-visual equipment. What the ads neglect to illustrate, though,
are the nuts and bolts behind these features. While everyone has watched
commercials that focus on a powerful V-8 engine, no one has seen a television
spot that emphasizes the electronic components found in everything from suspension
control to CD players. Granted, the electronics designed to make important
automotive safety and high-tech entertainment features are not as sexy as an
interior shot of heated leather seats and a sunroof, but without these features
many vehicles would lack the important elements that make them so popular with
buyers.
What many people do not know is that ceramics, and specifically ceramic passive
components, are used with great success in automotive electronics. They do not
realize that ceramics, some smaller than the tip of a pencil, can be used in
automotive electronic applications. Even within the automotive electronics
world, ceramic passive components are not always top-of-mind. Although 60% of
automotive passive timing devices are made from ceramics, engineering textbooks
barely mention their role in vehicles.
However, things are beginning to change. Ceramic components have become
exponentially more sophisticated while their size continues to decrease.
Further, automotive-grade ceramic passives can now be developed in large
quantities, reducing their cost while offering similar-and in some cases
improved-characteristics when compared to alternative materials.
In addition, as automotive
safety, communication and entertainment applications become more complex, the
ideal properties of ceramic components help make these new products possible.
Ceramics are also paving the way for the next generation of vehicles, hybrids
and other eco-friendly cars and features. Therefore, advanced ceramic components,
with their low cost, small size, improved reliability and ability to meet the
stringent demands of the automotive environment, are making important strides
in this market.
Ceramics Make Automotive In-Roads
Prior to World War II, the technology to turn
ceramics into passive components was lacking. Electronics found in products
like televisions mostly consisted of vacuum tubes. Cars were using electronics,
notably in radios, but ceramics were not a part of the design.
The situation began to change after the war, when companies experimented
with new ceramic manufacturing techniques. By controlling materials at the
molecular level before processing, molding and firing them, ceramics with
unique electric characteristics could be developed. Ceramic materials like
barium titanate and lead zirconium titanate (PZT) were manipulated to produce
components that, among other things, store electrical charges and protect
currents from excessive voltage. Soon ceramic components like filters,
capacitors and inductors were being used in a variety of products, including
household appliances. Ceramics were also made for consumer radios, but nothing
was developed specifically for automotive applications until later.
During the 1970s and 1980s, cars started to host more electronic
elements. New radios, 8-tracks and tape decks were in demand. Entertainment
features normally found in homes were making their way to cars. Companies that
already made components for consumer audio needs recognized that a new market
existed for automotive electronics.
The 1990s ushered in another trend that would make an important impact in the
automotive world and also necessitate the need for more electronics-the advent
of safety features. Air bags and anti-lock brake systems were just beginning to
come into favor. Today, cars offer even more safety features due to Federal
regulations and public demand. In fact, automotive electronic purchases for
cars have transitioned from mostly entertainment-based applications to safety
features.
Automotive Ceramics Today
Today, ceramic passive components can be
found in almost every aspect of a vehicle. Aside from air-bags, safety elements
in cars now include tire pressure monitoring systems (TPMS) that warn of unsafe
tire pressure, and back-up detection, which alerts
drivers to obstacles near the rear of the vehicle when reversing. Blind spot
detection is another beneficial safety feature. One of the main reasons why
ceramic parts are now considered for these features is that the improvements made
at the molecular level have increased performance reliability in automotive
environments.
For example, most automotive safety applications need timing devices to
work. Crystals
were traditionally used, but now more rugged and robust ceramic resonators can
replace them. In addition, the less-expensive ceramic component provides a
faster start-up time (related to frequency tolerance). The biggest change for
ceramic resonators is the vast improvement in total frequency tolerance over
the past 20 years, allowing for their use in all modern CAN-BUS applications.
Ceramics have been used in cell phones and other cordless products since
their inception, and are a perfect fit for wireless automotive technologies.
Components for electromagnetic interference (EMI) and microwave applications
are now in vehicles, while Bluetooth is being heavily touted for hands-free
features. The electronics behind remote keyless entry (RKE) also include
ceramics. In short, everything from navigation systems to satellite radio
utilizes capacitors, EMI filters, bandpass filters and numerous other baseband
and microwave components that are derived from ceramics.
Advancements have also ushered in new automotive technologies. In hybrid
vehicles, capacitors need to protect against charging circuits from voltage
spikes that occur when a car switches from gasoline to battery power. Ceramics
are best suited as snubber capacitors because they are smaller than
electrolytic and film-based capacitors, are non-polarized for easier application,
and work at 125ºF
and higher.
The Future of Automotive Ceramics
As cars become more reliant on electrical
systems for safety, entertainment and mechanical aspects, ceramic passive
components will continue to impact automotive electronics and increase in
demand. Some of the rise will be attributed to additional government safety
regulations requiring new electronic safety devices, but changes within the
general electronics market and further improvements to ceramic materials will
also play a role.
For example, the trend within the electronics market of modulization
(where individual active and passive components are combined together on a
miniaturized substrate) will also emerge in automotive electronics. Vehicle
makers and electronic suppliers are becoming less willing to spend the time
required to develop discrete solutions for existing and potential wireless
connectivity applications, such as Bluetooth, WiFi and WiMax. Modules,
especially those using ceramic substrates with embedded passives to minimize
the footprint, will allow engineers more time to design and focus on the
value-added functions of budding wireless technologies.
Wireless features promise to be popular, especially with the addition of
WiMax technology, which will be used not only for entertainment applications
but for traffic control and enhanced navigations options, just to name a few.
Again, ceramics lend themselves well to automotive wireless features because of
their small footprint, low cost and ability to withstand the harsh
environments.
Moving forward, an emphasis on research and development to further
upgrade ceramic materials will increase the popularity of ceramic-based passive
components for this market. Chemical constitution, the form of material particles
and grain size control technology at nanometer levels are all being studied in
an effort to further reduce the size of ceramic passive components while
increasing performance and reliability. Crystal
formation firing times and temperature profiles are also being considered,
since changes in these elements greatly affect electric properties such as a
ceramic’s ability to withstand voltage.
The beneficial properties
of ceramics and persistent improvements to their design and structure are
changing the way automakers are thinking about how these miniature-yet-reliable
components can be used in vehicles. No longer taking a back seat to tantalum, quartz crystal
and other materials, ceramic passive components will continue to make a
positive impact on automotive electronics and will only increase their presence
in this ever-evolving market.
For more information
regarding the use of ceramic components in the automotive industry, contact
Murata Electronics North America, 2200 Lake Park Dr., Smyrna, GA, 30080-7604;
(770) 463-1300; fax (770) 436-3030; e-mail ptiller@murata.com; or visit www.murata.com.Links