Substrate-to-heat-sink gap sizing in high voltage power converters

US11772788B1 · kind B1 · utility

Assignee

• ROLLS-ROYCE DEUTSCHLAND LTD & CO KG · DE

Inventors

• Uwe Waltrich · Forchheim, DE
• Stanley Buchert · Herzogenaurach, DE

Key dates

• Filing date: Aug 31, 2022
• Grant date: Oct 3, 2023
• Expiry date: Aug 31, 2042

Classification

• Technology area (CPC H): Electricity
• CPC primary: H02M7/5387
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

An electrical vertical takeoff and landing (eVTOL) aircraft includes an electrical propulsion unit that has a propeller or a fan configured to be driven to rotate by an electric motor arranged to receive electrical power from an inverter. The inverter includes a carrier substrate, and a converter commutation cell including a power circuit. The power circuit includes at least one power semiconductor switching element. Each power semiconductor switching element is comprised in a power semiconductor prepackage. A heat sink is arranged to remove heat from the respective power semiconductor prepackage. The heat sink is spaced apart from the carrier substrate to define a heat sink gap between the carrier substrate and the heat sink. A converter parameter φ, which is defined as a size of the heat sink gap divided by a maximum electric field strength in the heat sink gap, is less than or equal to 20 nm2/V.