Abstract
The existing European Directives for End of Life Vehicles (ELV) and the Restriction of the use of certain Hazardous Substances in electrical and electronic equipment (RoHs) represent a strong incentive to search for lead free manufacturing of automotive and industrial electronics. In the transition process, quality and reliability are key issues, with very high level requirements. This means that specific procedures must be used to guaranty the expected levels for the automotive and industrial applications.
This paper presents the work made to establish such a procedure. It is based on a qualification board, so called the "Q Board", fitted with most usual lead free active and passive components and equipped with an embedded autonomous tester allowing to probe on each board the electrical quality of joints and packages. This tester is based on an FPGA which is capable of detecting electrical micro-ruptures as short as 500 ns, and other electrical discontinuities, over more than 30 chains in parallel. Each of those electrical discontinuities is recorded in a flash memory, and the corresponding information on failure can be downloaded to a PC, after test. This on-board tester only requires 5V external supply, and its components have been selected for their high temperature reliability performances. This on-board tester is used for testing the board just after manufacturing, and, since it is autonomous, it can be used on any manufacturing site to validate its capability for lead free assembly and to qualify the packages in the corresponding manufacturing site processes. This tester is also used as a self diagnosis tool to monitor the solder joints and package reliability during the stress tests themselves and, since it is much cheaper and easy to move compared to conventional external test benches, many more boards can be analyzed under a large variety of conditions (temperature, vibrations, mechanical shocks...). The "Q Board" includes a large panel of automotive components, from passives to actives, including especially power devices so important in the automotive and industrial fields.
The corresponding procedure is explained and illustrated with cases. It will be shown to provide a suitable approach to switch onto Lead Free electronics for automotive on a very safe ground for design and manufacturing. The possibility to set a new standard is also offered.