Improving impact tolerance of portable electronic products: Case study of cellular phones

This paper uses analysis and high-speed photography to study the impact tolerance of cellular phones. Thin-walled clamshell case construction, which? is currently favored for portable products due to its size and weight advantages, may not provide sufficient rigidity to impact-induced loads, which can cause the housing to separate when dropped. A simple method for increasing case rigidity-castellation of the housing interface to prevent slipping of the case halves-that can substantially improve the product's drop tolerance is presented. implementation of variations of this technique in existing cellular phone designs allows the phones to surpass their drop survivability requirements. in addition, it is shown that the traditional construction method for cellular phone battery packs could lead to fracturing of the battery housing in a drop due to the multiple impacts that result. The authors describe a simple remedy-immobilization of the battery cells within the housing-that dramatically improves the battery pack's drop performance.