Search Results

This paper reviews the physics-of-failure model for accelerated thermal cycle tests of solder joints associated with various electronics components, summarizes the parameters of the automotive environment, and discusses the methods for developing thermal cycle tests for reliability validation for automotive electronics. The paper proposes an approach to develop the requirements for validation tests based on the customer usage profiles and the desired product life goal. This requirement determines the nominal testing duration based on the equivalent damage generated from the worst-case field applications.

Six Sigma methodologies in combination with Lean thinking have made considerable inroads as continuous improvement tools initially in manufacturing and more recently for service and transactional processes. There is considerable interest globally in training professionals on the use and application of these tools appropriate to either operational or transactional areas. It has long been realized that adult learning is at its best when participants are involved in relevant “hands-on” experiments. Six Sigma training has seen the use of class room demonstrations ranging from the use of playing cards, simulations and to the use of sophisticated experiments to illustrate concepts of factorial designs. This paper will focus on a series of simple but modular experiments that were developed over the past two years illustrating the application of all the Statistical tools that are taught as a part of Six Sigma Green and Black Belt body of knowledge.

An accelerated seat durability test was developed to identify potential problems in areas with traditionally high warranty cost and customer dissatisfaction: squeak & rattle and mechanism looseness & efforts. The test inputs include temperature, humidity, road vibration, occupant movements, and mechanism cycling. These inputs were combined into a single 14-day test profile that simulates 10 years and 250,000 km. (approximately 150,000 miles) of 95th percentile customer usage. Various components of the seat assembly are tested together as a system. The test was performed on two current production programs. The test produced issues similar to those found in warranty repair data and evaluations of used seats from high-mileage customer-owned vehicles.

Microprocessors and microcontrollers are now widely used in automobiles. Microprocessor systems contain sources of interrupt and interrupt service routines, which are software components executed in response to the assertion of an interrupt in hardware. A major problem in designing the software of microprocessor systems is the analytical treatment of interrupt latency. Because multiple interrupt service routines are executed on the same CPU, they compete for the CPU and interfere with each other's latency requirements. Here, interrupt latency is defined as the delay between the assertion of the interrupt in hardware and the start of execution of the associated interrupt service routine. It is estimated that 80% of intermittent bugs in small microprocessor software loads are due to improper treatment of interrupts. Until this work, there is no analytic method for analyzing a particular system to determine if it may violate interrupt latency requirements.

The automotive electronics market has seen and will continue to see unimpeded growth due to the substitution of mechanical and electromechanical devices with electrical devices wherever feasible for increased reliability. In addition, automakers are increasingly looking to incorporate advanced electronics technology into their vehicles to satisfy customer demands for more and innovative features. Examples of this are the use of global positioning system (GPS) for directions and roadside assistance and increased integration of the engine and powertrain to provide smoother, more fuel-efficient operation. Despite this growth, however, the automotive electronics market continues to shrink as a percentage of the total market due to the phenomenal growth of the computer and telecommunications markets.