The present invention provides microelectronic component assemblies and lead frame structures that may be useful in such assemblies. For example, one such lead frame structure may include a set of leads extending in a first direction and a dam bar. Each of the leads may have an outer length and an outer edge. The dam bar may include a plurality of dam bar elements, with each dam bar element being joined to the outer lengths of two adjacent leads. In this example, each dam bar element has an outer edge that extends farther outwardly than the outer edges of the two adjacent leads. The outer edges of the leads and the outer edges of the dam bar elements together define an irregular outer edge of the dam bar. Other lead frame structures and various microelectronic component assemblies are also shown and described.