Material inspection
US6697151B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 2001 |
| Grant date | Feb 24, 2004 |
| Priority date | — |
| Expiry date | Oct 4, 2021 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K3/08
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
An inspection station (6) has a ring of 370 nm LEDs (24) for low-angle diffuse illumination of flux. This stimulates inherent fluorescent emission of the flux without the need for flux additives or pre-treatment. A CCD sensor (20) detects the emission. An image processor generates output data indicating flux volume according to a relationship between emission intensity and volume over the surface of the flux. Intensity non-uniformity indicates either height non-uniformity or hidden voids, both of which give rise to defects after application of solder paste and reflow. The inspection is particularly effective for pre solder application flux inspection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.