2 layers125 × 83.7 mm

The BD677 is a darlington Transistor made by DDF in a TO-126 package with 3 pins. TO-126 Darlington Transistors ROHS.
210 are in stock at JLCPCB (part C50229441). 1 open-source board in 1 repository on GitHub use it.
The library has no symbol for this part yet.
The library has no footprint for this part yet.

TO-126, with 3 pins.
DDF publishes it: the Datasheet link on this page opens it.
JLCPCB lists it as part C50229441, with 210 in stock; the sellers' links on this page open their listings.
1 board in 1 repository on GitHub; the most starred are listed on this page, with their KiCad files.