This part is a kind of semiconductor called 2SD1270.

Function of this product has Silicon NPN epitaxial planar type(For power switching).

Manufacturers : Panasonic Semiconductor

Image and pinout :

Some of the text within the PDF file :

Power Transistors 2SD1270 Silicon NPN epitaxial planar type For power switching Complementary to 2SB945 0.7±0.1 10.0±0.2 5.5±0.2 2.7±0.2 4.2±0.2 Unit: mm 4.2±0.2 s Features q q q q Low collector to emitter saturation voltage VCE(sat) Satisfactory linearity of foward current transfer ratio hFE Large collector current IC Full-pack package which can be installed to the heat sink with one screw (TC=25˚C) Ratings 130 80 7 10 5 40 2 150 –55 to +150 Unit V V V A A W ˚C ˚C 7.5±0.2 16.7±0.3 φ3.1±0.1 4.0 1.4±0.1 1.3±0.2 Solder Dip s Absolute Maximum Ratings Parameter Collector to base voltage Collector to emitter voltage Emitter to base voltage Peak collector current Collector current Collector power TC=25°C dissipation Ta=25°C Junction temperature Storage temperature [ ... ]

2SD1270 PDF Datasheet Download