Approximate Engineering Theory for the Twisting of Compliant Leaded Circuit Card/Module Systems

Abstract

Twisting is a favorite method of product assurance testing agencies for verification of robustness. The geometry of flexure is simpler, and structural analysis benefits from the symmetries. This chapter will introduce the basic problems involved in the twisting of circuit cards, and an approximate solution will be shown for a single module attached to a card. This approximate treatment, while useful in defining some concepts, also produces acceptable results for relatively widely spaced stiff leads in plastic modules. (The reader may skip to the next chapter for an analytical theory, confirmed by finite element analysis.) The procedure is extended to the analysis of module groups.