This application note provides guidelines for mounting various types of STAC® packages in amplifiers or application boards (PCB) by means of bolting or by soldering. Specific attention is paid to the STAC244B and STAC265B boltdown styles and the STAC244F and STAC265F flangeless styles, which are used to encapsulate numerous VDMOS and LDMOS technology products.
This document serves as a technical guide for mounting STAC® RF power transistor packages (specifically the STAC244B/STAC265B boltdown styles and STAC244F/STAC265F flangeless styles) onto amplifiers or PCBs. It addresses mechanical stress, thermal resistance, and electrical reliability in application environments.
The note details procedures for both bolting and soldering methods, including hardware requirements, torque specifications, and core preparation. It also covers the selection of heatsinks, thermal interface materials (TIMs), and specific considerations for epoxy-sealed non-hermetic packages regarding moisture sensitivity and baking conditions prior to assembly.
| Moisture Sensitivity Rating (MSL) | 3 |
|---|---|
| Recommended Baking Temperature | 125 °C |
| Baking Duration (at 125°C) | 24 hours |
The document focuses on the STAC244B and STAC265B boltdown styles, as well as the STAC244F and STAC265F flangeless styles.
It is advised to bake non-hermetic packages for 24 hours at 125 °C prior to soldering operations.
The junction temperature was maintained uniformly below the maximum allowable temperature of 200 °C.