Limitations and cautions:
This IC is a “hybrid” module, meaning it combines multiple discrete components (transistors, resistors, and diodes) on a ceramic substrate, all housed in a single insulated package. This design approach offered manufacturers a balance between the performance of a discrete component amplifier and the convenience of a monolithic IC. Stk411-210e Datasheet
Always use high-quality thermal paste and an appropriately sized heatsink. Operating the IC without a heatsink will cause immediate and permanent failure. Ic Stk411 210e(968) - Alibaba Limitations and cautions: This IC is a “hybrid”