Feature-based design is an approach that promises substantial benefits in capturing and transferring a designer's intent to other stages of design and manufacturing, thereby helping to integrate the diverse functions associated with design and manufacturing. While feature-based design has considerable potential, it has been applied almost entirely to mechanical design. Furthermore feature-based design has been implemented in a relatively ad hoc manner and, consequently, much of the work on feature-based design cannot be readily applied to other domains. This paper aims to address some of this deficiency by describing a feature-based design system for electronic manufacture that is based on the firm formalism of a feature algebra and a feature-based design algorithm. An electronics assembly feature taxonomy is developed, together with feature operators and validation scheme. These are used to build a prototype feature-based design system called Feature-Based Design of Electronics Assemblies (FEBEA). The format of this paper is as follows. The representation formalism is briefly described. The electronics assemblies design domain is then detailed. The design domain is formally defined and an electronics assemblies design module is constructed. A testability evaluation module is then developed. Finally the prototype implementation of FEBEA is described, and how design is represented and performed using FEBEA is illustrated through an example design scenario. The contribution of this paper is, first, to place the feature-based design of electronics assemblies on a firm formalism foundation. Second, to develop a feature taxonomy for electronics assembly design. Third, to define feature operators and feature validity for electronics assemblies. Fourth, to develop a feature transformation scheme for testability evaluation. Finally, to show how such a feature-based approach can be implemented. The overall result is an approach that allows the designer to design an electronics assembly iteratively, taking into account the available components, constraints on such aspects as component placement, and taking into account Concurrent Engineering constraints. It would appear that the underlying approach could be applied to other domains.