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54 The PCB Design Magazine • February 2017 by area array packaging—the potential to de- sign assemblies with every component having termination that could land on a standard grid. It is arguable that this is one of the most im- portant and still largely ignored benefits offered by area array technology. It is a benefit that pro- vided the opportunity to make electronics in- dustry more coherent than it has ever been. The simple truth is that great benefit can be achieved by establishing a fundamental base grid pitch for all interconnections. This will allow for the creation of an underlying standard that will provide a much clearer view for the future. The logic is compelling that a single standard grid pitch for interconnection will allow for all elec- tronic elements of an electronic assembly to be manufactured, tested and assembled in an al- most snapped-together fashion, something akin to the children's construction toy Lego. Figure 1 illustrates how the termination on a common grid works. Stepping back in time as alluded to earlier, coherent integration of electronic elements based on a standard grid is not really a new idea. IBM used the method internally with great suc- cess for many years with its through-hole inter- connected devices. They even mass-produced PCBs with thousands of holes on grid suitable for personalization when and where required. The standard grid was also used by the rest of the industry and it was based on a 100-mil grid THE BENEFITS OF EMPLOYING A STANDARD GRID PITCH IN DESIGN Figure 1: Basic common grid. Figure 2: A variety of lead pitches shown at left, compared to the common grid on the right.