Laser roughening to improve LED emissions

US7749782B1 · kind B1 · utility

Assignee

• Palo Alto Research Center Incorporated · US

Inventors

• Clifford F. Knollenberg · San Bruno, US
• David P. Bour · Cupertino, US
• Christopher L. Chua · San Jose, US
• Jeng Ping Lu · San Jose, US

Key dates

• Filing date: Dec 17, 2008
• Grant date: Jul 6, 2010
• Expiry date: Jan 22, 2029

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S438/964

Abstract

An improved method of forming a LED with a roughened surface is described. Traditional methods of roughening a LED surface utilizes strong etchants that require sealing or protecting exposed areas of the LED. The described method uses a focused laser to separate the LED from the substrate, and a second laser to roughen the LED surface thereby avoiding the use of strong etchants. A mild etchant may be used on the laser roughened LED surface to remove unwanted metals.