Thermal Performance Analysis and Study on one Top Side Cooling discrete package for xEV OBC Application

Inhalt:
To address the thermal challenge of higher power density in on-board chargers (OBCs), this paper conducts an in-depth analysis and study of the system thermal characteristics of top side cooling (TSC) discrete power devices with finite element thermal simulation. Based on simulation result, it reveals the TSC packaging has a higher system thermal resistance compared to traditional through-hole and bottom-side cooled packages. To optimize the system thermal resistance of TSC package, both internal structural parameters of the package and different external assembly methods are investigated. It is found that the leadframe size and soldering material of TSC devices affect both the device's own thermal resistance RthJC and the system thermal resistance RthJW. Moreover, the externally assembly with direct bonded copper (DBC) can effectively reduce the external case to heat sink resistance RthCH directly. furthermore, a thermal performance comparison is made with another TSC devices concept of DBC inside on the market. Finally, the paper concludes with a summary.