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Testing Todd: A Summary of Various Test Requirements

IPC Class 3

The PCB industry has advanced significantly in the recent millennium. OEM specifications and requirements have also advanced due to the maturing of technologies, which has caused the requirements of electrical test of these higher technology products to advance and increase in intensity. Obviously, the more mature a technology, the finer the lines and spaces must be, the more hole and vias must be present, and the more complex the testing must become. There is just more to test in a smaller amount of space.

Long gone are the “pin-in-hole” technology PCBs, which are now surpassed by the large multilayer, blind/buried and rigid-flex technologies. For the suppliers of electrical test, be it in-house test departments or sub-contracted, the industry specifications can be confusing, and at times incomprehensible.

The OEMs direct the IPC specification (6012, 9252A, AS9100, etc.) for their fabrication to the manufacturer, but in many cases do the OEMs or CMs really know what they are asking for? Do they really understand what they are requiring and how complicated it may be?

There are many variables associated with these specifications and requirements to their designated classes regarding electrical test. OEMs  often overlook the electrical properties associated with IPC class performance requirement, and  of course, this can be a problem. Manufacturing, plating, etching and all those processes may be within the class requirements.

During the coming months, I will discuss various aspects and intricacies of electrical test. To get started, I will address IPC class 1, 2, and 3

Class I: General Electronic Products

This class includes consumer products, some computer products and computer peripherals suitable for applications where cosmetic imperfections are not important, and the major requirement is function of the completed board.Read the full column here.Editor's Note: This column originally appeared in the April 2014 issue of The PCB Magazine.