Ring illumination apparatus for illuminating reflective elements on a generally planar surface
US5943125A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 1997 |
| Grant date | Aug 24, 1999 |
| Priority date | — |
| Expiry date | Feb 26, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/8806
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An inspection system and method uses a ring illumination apparatus to illuminate one or more reflective elements, such as solder balls on an electronic component or other protruding surfaces or objects. The ring illumination apparatus includes a substantially ring-shaped light source that provides a substantially even illumination across the one or more reflective elements. An illumination detection device detects light beams reflecting off of the illuminated reflective elements for forming a reflected image. A method of processing the reflected image includes locating one or more edges of each reflected image element representing an illuminated reflective element. The edges of the reflected image elements are located by determining the maximum intensity gradient in the pixels forming the reflected image element. The inspection system and method thereby determines various characteristics such as the absence/presence, location, pitch, size and shape of each reflective element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.