Ball grid array (BGA) package on-line non-contact inspection method and system
US6525331B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 1999 |
| Grant date | Feb 25, 2003 |
| Priority date | — |
| Expiry date | Dec 1, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/8806
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus is disclosed for non-contact, on-line inspection of objects including a ball grid array package by means of a shadow moiré technique combined with a novel flash phase-shifting method. The grid pitch size, ball height, ball diameter, missing ball, coplananity can be determined or measured within several seconds. The apparatus includes a camera for viewing the object, a plurality of light sources arranged in a line for illuminating the object to be inspected, a frame grabber for capturing images of the object, an I/O adapter card for controlling the light sources and a personal computer for data processing. The individual components are integrated into system which provides a three dimensional map which is obtained quantitatively using a novel algorithm. The system can provide coplananity data, as well as data relating to grid pitch, ball height, ball diameter, and missing ball information.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.