Journal of SMT Article

Design for Excellence: Inductor Form, Fit, Function Equivalence & New Design Rules

Authors: Matt Kelly, Mitch Ferrill, Mark Jeanson, Jesus Montanez, and Timothy Jennings
Company: IBM Corporation and Celestica International
Date Published: 10/1/2017   Volume: 30-4

Abstract: Today, it goes without saying; digital electronics are found nearly everywhere. Applications ranging from cellular/mobile markets to automotive electronics; from consumer electronics to avionics/ military control systems; and from medical devices to enterprise server and storage ‘big data’ compute systems. Although very different in application, they all have something in common; they nearly all contain inductors within their circuit design architectures. Inductors are passive electrical components that are used in analog, power, and signal processing. Electronic circuit designs and applications span power supplies, tuned circuits, transformers, limited switching currents, inductive sensors, inductive filters, chokes, and relays (among others).

Over the past two years, significant work was conducted by the authors in the areas of inductor part equivalence, PCBA physical designs using inductors, and increased understanding of important reliability considerations.

The paper discusses the findings from this work with focus on two critical elements important to the operation and reliability of coil inductors. These focus items address (1) the evaluation of component physical form and fit equivalence of inductors and (2) the implementation of new design review tools and rules intended to keep functionally unrelated vias, power/ground shapes, and signal traces outside of inductor body areas.

The intent of the paper is to discuss the importance of properly determining inductor equivalence, and to discuss new automated software tool capability that has been developed to ensure highest quality implementation of inductors within Enterprise Class Server and Storage hardware.


design for excellence, inductors, inductor equivalence, automated design review tools

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