Another hurdle that components have to overcome before they are placed in vehicles is the reliability issue. Currently, there is no worldwide standard for automotive grade reliability. In the United States, AEC-Q200 was established by the Big Three automakers to define common electrical component qualification requirements, testing methods and guidelines. However, Japan and Europe use different testing benchmarks. For example, while all vehicle makers need components to pass a stringent heat cycle test, the temperature as well as the minimum number of cycles needed to achieve automotive grade vary considerably. As a result, electrical components must be custom made according to each manufacturer's specifications

At Murata Electronics, engineers created an internal reliability specification to satisfy the differing demands. This helps reduce cost and assures that all ceramic components destined for vehicles meet the variety of automotive grade standards.

Moisture
Exposure to rain, snow, salt, and humidity can damage various parts of a car or truck—electronic components included—so car makers take numerous steps to prevent it. For example, many manufacturers place a protective coating on printed circuit boards. This coating however, can enter into the casing of a conventional CMCC because of a slit in the packaging. Once the coating compromises the CMCC, the wire interior can "escape" due to the temperature expansion differences between the coating and the CMCC body. To prevent this, automotive grade CMCCs are made without the slit. In order to achieve this advanced design, a new manufacturing machine was invented.

Mechanical strength
A typical consumer-electronics component is generally not subject to the constant stress and use seen by automotive electronics. Endurance becomes an important factor and, without adaptations, passives cannot handle the abuse. However, electronic makers who invest heavily in research and development have created sophisticated methods that improve ceramic materials so that they can take the constant punishment and make automotive grade.

Using CMCCs again as an example, the ferrite core structure has been redesigned. Unlike the material changes needed to combat heat, the basic shape of the core itself was altered. Then, using an advanced stress evaluation computer simulation, the CMCC was tested and, through software analysis, deemed capable of proper function in a difficult automotive environment.

Outlook
Cars of the future will only increase their reliance on electronics and passive components. With the addition of sophisticated entertainment technology and advanced safety features, ceramics will continue to be in great demand. Requirements for automotive grade components may change again, but companies who use innovative materials, adaptable designs, and cost-effective production methods will have no trouble placing components aboard even the most complex vehicles.

Yuji Nakanishi is automotive manager for Murata Electronics North America.