Bare Board X-ray Inspection: Start at the Base

摘要

THE OPERATION AND reliability of any electronic assembly is as dependent on the performance, quality and consistency of the bare printed circuit board as it is on quality components and a sound manufacturing process. Without quality bare boards, however excellent the assembly process, whole batches of product will be at risk of failure, as they will have been built on an inherently bad foundation. Add the possibility that the boards may be stored for long periods before being used, perhaps in suboptimal conditions, and we have a recipe for problems within that basic foundation. Bare board quality today is usually so good that many will not expect it to be the cause of an issue until much, much later in the "blame game" of root cause analysis. Assemblers will typically focus first on examining and clearing what they (may) have done, then look at the components. (Remember, everyone at first blames the BGA!) Therefore, appreciating how bare boards are manufactured, understanding their potential areas for failure and having access to appropriate inspection facilities should allow, in principle, those involved in incoming/receiving, or the first step of the assembly process, to identify and minimize bare board issues ahead of release to assembly.