Build a realistic loss and temperature budget
Use the device losses for the operating conditions, including switching and conduction effects. Map device positions and thermal coupling. Include attachments and interfaces rather than assuming the ceramic is the only significant resistance.
Compare established power constructions
Alumina DBC can provide a baseline, while AlN or tougher substrate systems may address specific thermal or cycling constraints. Compare completed copper-clad constructions and verify electrical isolation under the relevant conditions.
Control assembly and production variation
Die placement, attach voids, wire bonds and baseplate interfaces can change local temperatures and stress. Define inspection and process controls that keep the validated design representative of production. Monitor critical interfaces rather than relying on a single final electrical test.
Engineering example
Unequal cooling under neighboring switches can create different operating temperatures despite identical devices. Evaluate the full substrate and cooling geometry when balancing thermal performance.
Before you release the design
- Provide device losses and placement.
- Specify substrate and cooler interfaces.
- Define attachment and reliability acceptance.
Sources and further technical reading
Manufacturer references support the material and process context. Worked examples and checklists are engineering guidance; they are not test results or supplier guarantees.