Glossary comparison
Power cycling vs Thermal cycling: what is the difference?
The difference
Thermal cycling heats and cools the whole module from outside with no current, mainly stressing the substrate-to-baseplate solder. Power cycling heats from inside the chips and mainly stresses the die attach and bond wires.
Power cycling heats the chips with load current, so the hottest points are inside the module and the die attach and bond wires take most of the stress. Thermal cycling heats the whole module from outside with no current flowing.
The two terms
Power cycling
A reliability test in which a module is repeatedly self-heated by load current and cooled, producing large junction temperature swings. It targets the die-attach and bond-wire interfaces and is quoted as cycles to failure for a given delta T.
Thermal cycling
A passive test in which the whole assembly is cycled between temperature extremes in a chamber, stressing the joints between materials of differing expansion coefficients.
Side by side
| Field | Power cycling | Thermal cycling |
|---|---|---|
| Stands for | Not an abbreviation | Not an abbreviation |
| Type | Process | Process |
| Domain | Power & Discretes | Power & Discretes |
| Group | Thermal and reliability | Thermal and reliability |