Overvoltage protection device

US6639253B2 · kind B2 · utility

Assignee

• Bourns, Inc. · US

Inventors

• Russell Duane · Cork, IE
• Jeremy Smith · Loudon, US
• Steven Wilton Byatt · Bromham, GB

Key dates

• Filing date: Apr 4, 2002
• Grant date: Oct 28, 2003
• Expiry date: Apr 4, 2022

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D89/10

Abstract

A semiconductor overvoltage protection device in the form of a four layer diode has first and third layers of a first conductivity semiconductor material, second and fourth layers of a second conductivity type semiconductor material and a first buried region of the first conductivity type in the third layer adjacent to the junction between the second and third layers. The buried region has a greater impurity concentration than the third layer. The first layer is penetrated by a plurality of dots of the second layer extending through the first layer and the first buried region lies wholly beneath the second layer and is laterally offset from the dots and the first layer.