UCC5390: Some questions.

Hi team,

My customer considers using UCC5390.
Could you tell me about the following questions?

Q1. The datasheet said UCC5390 has an Isolation Barrier Life over than 40years.
       What are the conditions for 40 years or more?

Q2. What is the failure mode when the dielectric breakdown of UCC5390?

Sincerely.
Kengo.