Robustness Validation

Robustness evaluation or engl. robustness validation is a qualification strategy, with which the robustness of a product is demonstrated to the load conditions of an actual application and specific statements about risks and reliability can be made. This strategy is, especially in the automotive industry for use.

History

At the beginning of the 1970s were still relatively high failure rates of electronic components in automobiles tolerable, because they replaced mechanical components, which had a much higher failure rate. The underlying failure rates of bimetal flashers were 10 % per year and the lifetime of mechanical ignition contacts at 10,000 km. With the increasing number of semiconductors in the control units and the introduction of the first safety systems (ABS ) was developed in the 70s, other action. As early as 1975 the General Specification for IC's was issued in Automotive Applications SAE as the first recommendation, which was declared in 1978 to the SAE standard and adopted by the major semiconductor manufacturers.

The establishment of the Automotive Electronic Council ( AEC) in 1994 by Ford, Chrysler, GM- Delco was also the starting point for the AEC Q100 qualification process based on the SAE standards.

Characterized by this method is non-specific tests, which are intended to cover a wide range of possible failure mechanisms, but rule only on functionality of the component. Due to the development of automotive electronics and the ever-increasing complexity in the vehicles connected with the demands for lower error rates of this qualification procedure is no longer appropriate. In order to make statements about the robustness, AEC Q100 to be replaced by Robustness Validation.

Initiators and contributors

In April 2007, the Handbook for Robustness Validation of Semiconductor Devices in Automotive Applications was posted in international cooperation by the SAE, ZVEI, AEC and JSAE (Japanese Society of Automotive Engineers), in which the guidelines for the timely validation of semiconductor components for use in automobile are summarized. Involved in this case have companies from the supply chain in the field of automotive electronics. In addition to vehicle manufacturers and suppliers has completed with a current database, a large group of semiconductor manufacturers, this concept of skill. This so-called Knowledge matrix contains a list currently known failure mechanisms with causes error methods and further information.

Content

Robustness Validation is to assess the reliability of electronic components by the specific requirements are compared to the product with the actual " values ​​of life ". With the introduction of this methodology a concrete list of requirements (usually starting from the OEMs ) are required. The requirements for the product are divided into the environmental requirements ( mission profiles) and the functional requirements ( use cases ).

Mission Profile

The mission profiles describes the loads and stresses acting on the product in real use. These are, for example, changes in temperature, temperature profile, vibration, and the interaction of electrical and mechanical fields or other environmental influences. It is necessary to specify the relevant stressors in their nature, intensity and duration of exposure, as well as the mix as accurately as possible. These details are given in the context of given accuracy possible projections in terms of reliability of the application and its components in the field.

Use-Cases

The use cases describe the nature and frequency of the operating conditions for which the product is designed. Please make sure that this addition to the normal operation, the possible cases of special operation and emergency operation. This meaning is not permissible, knowingly abuse.

Robustness Margin

The hedged lifetimes are determined by specific, tailored to the application and the failure mechanism tests. An essential processes are end-of- life tests. From the spacing of the requirements on the test results the reliability and robustness of the device can be determined.

Product Development

Today's standard qualification procedures for electronic components, assemblies and components for the automotive sector, based on the use of standardized tests at the end of the product development of the devices and components. In contrast, Robustness Validation is a process that includes the entire product development process, as well as mass production. The qualification of components based on the robustness analysis is thus implicitly. With the introduction of Robustness Validation priorities are defined in the development process. The aim is to reduce the error's construction during the later project phases, through a frontloading measures must be simultaneously carried out in the product development process.

It was required to break down the requirements from the product to the next level of the value chain in order to meet specific statements on the possible vulnerabilities can be. Back in the early phases of the project is the knowledge (eg, from knowledge databases, Lessons Learned ) resorted previous projects in order to avoid known vulnerabilities documented. Using the analysis of the changes of the new product and the use of different methods such as FMEA, DRBFM or design reviews, new potential vulnerabilities are identified in order to analyze potential risks occurring early and avoid them. The hereby presented the critical parameters used for the analysis of the feasibility of the project and, where appropriate, to flow with the change in the initially prepared product requirements with a. In the validation of the proof of the functional feasibility and reliability takes place, wherein the functional performance and the implementation of the specification to be checked.

Further areas of applicability Robustness Validation

In addition to the publication of the Handbook for Robustness Validation for semiconductor devices in 2007 was another manual Released in which this procedure is described for the development and qualification of electronic control units in automobiles in the ZVEI in the year 2008. There are more activities in the field of sensors and electronic systems in the vehicle.