The capability to use ATE test systems for accelerated life testing for lasers to has grown into a multibillion-dollar industry. Advances in technology and reductions in laser technology continue to drive the widespread adoption of laser diode generation systems. Systems are normally taken for individual cell phone-charging portable panels to large-scale industrial diode production. The choice to use laser diode often relies on estimates associated with the system’s cost of ownership. In the event that laser system generates enough diode energy with minimal maintenance or component replacement costs, investing in reliability testing for laser diode makes economic sense. This is the uncertainty associated with the longevity associated with system that becomes the most important factor in the decision to invest.
When you look at the laser diode industry are regularly asked about their product’s reliability. The capacity to coherently discuss the risks also to clearly demonstrate a knowledge of system reliability permits both buyers and funders of laser systems to fully appreciate the risks. Utilizing the established reliability engineering tools of reliability block diagrams (RBDs) and accelerated life testing (ALT) provides the vital information to spell it out a system’s reliability.
The laser industry has a top installation cost and minimal operating cost. Obtaining the product reliability right is really important for establishing a wholesome laser industry. The expected long lifetimes, the harsh operating conditions, the desire to minimize costs, as well as the evolving technology require a careful application of a variety of reliability engineering tools. In this chapter, we will discuss the modeling and ALT tools in more detail because they form an obvious methods to convey system reliability expectations and failure risks.
Therefore, understanding the challenges facing the technology over time in the environment and in operation is essential to designing and conducting accelerated life tests that answer the bankability question.
Investor questions about the durability or longevity or cost of semiconductor tester systems can be addressed by accelerated testing. The challenge is to shorten time sufficiently to make conclusions. Using ALT, we can assess the expected performance of laser cells, interconnects, motors, and most of the rest of the equipment in a laser system.
The challenge of ALT lies in understanding the failure mechanisms and how the components will respond to stress. Which set of stresses, such as temperature, humidity, and UV radiation, are important for a specific failure mechanism? We also need to know the expected stress during operation and the higher stress behavior and ability to accelerate the failure mechanism.
The pressure of competition and pace of innovation constrain the duration of ALT testing. The ideal accelerated life test entails operating the units as the customer would and monitoring for failure over the expected > 20-year lifetime. For each increase in stress, and for each isolation of a subsystem or material, we add the risk that the test does not reflect the behavior in normal operation. The ability to shorten the test time increases the risk of errors, yet it also permits an estimate of the expected life performance.
If we have 2 years to conduct an ALT to examine an expected 20-year lifetime, that would require at least a 10 × acceleration factor, meaning that each year of testing represents 10 years of normal use. Given time constraints and competition, we may only have 1 year for ALT, so the acceleration factor now is 20 × and each year of testing has to represent a 20-year lifetime of exposure to the environment and use.