the BCW66K has a thermal resistance of 70K/W @TS=115°C compared to 215 K/W of the BCW66. Is there really a difference in the thermal design or is it just a different presentation methode? I know that the BCW66 is obsolet, but I want to understand the difference in the two datasheets.
Thank you for posting your question Infineon community.
The BCW66 and BCW66K are different packages and the power dissipation capacity is also different.
The Ic(Collector current) will be the main parameter to change the Rth for any device.
Maybe if you can specify the exact part numbers it would be good to compare. comparing only thermal parts is not
fair so electrical parameters also contribute here