Keep the insulation mechanisms separate
Clearance is a path through air; creepage follows an insulating surface; solid insulation is through the material. Different conditions govern each. Contamination, altitude, humidity, field concentration and coatings can affect the completed assembly.
Do not multiply a catalog value into a rating
A kV/mm test value has a stated specimen, method and duration. Multiplying it by thickness is not a qualified working-voltage calculation. Determine the required insulation system and tests using the applicable product requirements and qualified engineering review.
Review copper edges and interfaces
Copper-to-edge spacing, etched profiles, braze regions, vias and encapsulation interfaces influence local electric fields. Partial discharge and surface contamination can matter even when a simple withstand test passes. Include actual package materials and operating conditions in validation.
Engineering example
A substrate that passes a short dielectric withstand test may still require additional partial-discharge and environmental assessment for its intended service. The two tests answer different questions.
Before you release the design
- Define working voltage, transients and insulation function.
- Use the applicable product standard and test conditions.
- Evaluate the assembled geometry and interfaces.
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.