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82 The PCB Magazine • August 2016 The days, weeks, and (sometimes) years that go into a product's development usually are in- comprehensible to the lay person. Like laws and sausages, no one wants to really understand what has gone on behind the scenes to make your "thing" a reality. They just care that your widget makes their life easier and/or more en- joyable! With that, design and development kick off the process which eventually takes your wid- get from a "light bulb" idea all the way to ac- tual production, but ultimately the testing that has been performed along the way shapes your widget into something that is reliable and thus more attractive to your customer. At the core of this reliability-based testing is exposure of your widget to various potentially harmful environments. These potentially dev- astating environments help designers and en- gineers identify weaknesses in the product and, hopefully, identify ways to make your widget better! Generally speaking, there are two main categories of reliability exposures—mechanical and climatic. This is not to say that there are not other types of harmful environments; like an exposure to hazardous vapors or subjecting your widget to electromagnetic interference, but mechanical and climatic are the more tra- ditional types and we'll explore those in a bit more detail in this column. Mechanical Exposures Generally speaking, mechanical test expo- sures involve hitting your widget with a large singular force or with a smaller repeated force at a high frequency. The large singular force expo- sure is traditionally referred to as a mechanical shock, whereas the repeated force at high fre- quency is traditionally referred to as vibration. For mechanical shock, the widget is typically dropped from a specific height, onto a hard sur- face, with the widget checked for functionality pre- and post-exposure. Further, these types of shocks can be repeated or increased / decreased by Keith M. Sellers NTS-BALTIMORE Welcome Your Product to the Real World! LET'S TALK TESTING