A heat spreader (20) is added to a package to enhance thermal and advantageously electrical performance. In manufacture, a heat spreader precursor (24) is advantageously placed over a group of dies and secured after bonding (e.g., wire or tape bonding or flip-chip bonding) and before matrix/block mold. For example, a package strip (10) may consist of a row (linear array) of groups of die attach areas (e.g. in a rectangular array of four). The heat spreader precursor (20) may accommodate one such group or multiple groups along the package strip (10). The package strip (10) may then be singulated to form the individual packages. Each singulated package includes a die (14), its associated substrate 16 (e.g., either a lead frame or interposer type substrate) and a portion of the heat spreader precursor (24) as a heat spreader (20).