The use of JEDEC θJA, θJC, or ΨJT thermal parameters for application system thermal estimates is not recommended as indicated in the JEDEC51 specification. This methodology is not meant to and will not predict the performance of a package in an application-specific environment. Therefore, these parameters are no longer provided in the device datasheet.
The thermal models can be found on the specific processor's webpage in the "Tools & Simulations" section, and we need to import them into the thermal software.