A lead frame structure of a light emitting diode includes a ceramic bed, a metal layer and a plastic seat. The metal layer has a first metal circuit area, a second metal circuit area, a gap dividing the first metal circuit area and the second metal circuit area, and a metal ring surrounding the first metal circuit area, the second metal circuit area and the gap. The plastic seat has a hollow function area. The first metal circuit area, the second metal circuit area and a part of the metal ring expose the function area to make the metal (circuit) layer of the function area has no gap to avoid excess glue. This can efficiently accomplish to increase intensity, quality and reliability of the packaged products.

The invention provides a transistor outline (TO) packaging structure, which comprises a lower substrate, the lower substrate comprises a lower ceramic substrate, a lower conductive layer and a lower heat dissipation layer, an upper substrate, the upper substrate comprises an upper ceramic substrate, an upper conductive layer and an upper heat dissipation layer, a chip located between the lower substrate and the upper substrate, a molding material layer covering the chip and covering part of the lower substrate and the upper substrate, and a metal tab comprising an pin hole, wherein when from a cross-sectional view, a top surface of the upper substrate, a top surface of the metal tab, and a sidewall of the molding material layer form a stepped structure.