Apparatus and process for detecting inclusions

US7307714B2 · kind B2 · utility

Assignee

• CORNING INCORPORATED · US

Inventors

• David G. Cyr · Corning, US
• Christopher Paul Daigler · Corning, US
• David R. Fladd · Summerville, US
• David C. Jenne · Hammond, US
• Albert Roth Nieber · Corning, US
• Nikki Russo · Alpine, US
• Paul John Shustack · Sharonville, US

Key dates

• Filing date: May 20, 2005
• Grant date: Dec 11, 2007
• Expiry date: Apr 25, 2026

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N21/8803
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Disclosed are process and apparatus for inspecting internal inclusions in internally transmissive substrates. The process involves applying a black coating to one major surface of the substrate, submerging the substrate in a refractive index-matching fluid, and scanning the substrate with a collimated light beam. The scattered light signals produced by the inclusions can be detected by the human eye or by using a light detector. By the use of index-matching fluid and the black coating, the signal-to-noise ratio of the process and apparatus are enhanced. A preferred black coating is one cured from an electron beam or photo polymerizable coating composition applied to the major surface. The process and apparatus are particularly suitable for inspecting internal inclusions in an internally transmissive substrate having considerable amount of surface defects or contoured surface that prevent it from inspection in a gas medium.