Solder joint inspection system and method
US4988202A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 1989 |
| Grant date | Jan 29, 1991 |
| Priority date | — |
| Expiry date | Jun 28, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/102
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention is an automated solder joint inspection system for determining the quality of a specular soldered joint through examination of the shape of the joint surface using a series of point light sources and the associated highlight reflections from the joint surface. The light from point light sources, which is directed toward the solder joint, is reflected in a pattern from the solder joint to an array of light responsive transducers from at least one location. Utilizing the intensity values from the light responsive transducer array, the surface orientation of the solder joint at a number of points is determined. The solder joint is evaluated in one of two ways. In one way, using known surface features of solder joints along with curve fitting techniques, a series of grid maps is mathematically interpreted to reconstruct the solder joint surface. A rule-based system, through comparison with acceptable solder joint surface features, evaluates and classifies the joint for an acceptability determination. In another way the surface orientation is used to generate an Extended Gaussian Image of the joint and the features of this are analyzed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.