Apparatus and method using photoelectric effect for testing electrical traces
US6369591B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1999 |
| Grant date | Apr 9, 2002 |
| Priority date | — |
| Expiry date | Dec 15, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/309
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A tester for electrical traces such as on a circuit board generally comprises an electromagnetic beam source such as a laser producing an ultraviolet beam, a vacuum chamber, an electrode circuit including electrodes and corresponding electronics including ammeters for measuring photoelectron flow between traces and electrodes, a controller, laser beam optics, an image acquisition system, and a pair of broadband UV lights. The board containing traces under test is disposed in the vacuum chamber at lowered pressure with grid electrodes lying close to the trace area on each side of the board. Electrode electronics selectively maintain a known potential on each electrode. The exact location of traces are determined by an image acquisition system. The board and traces are initialized to a known voltage. Photoelectric effect using ultraviolet laser beams is used to determine continuity between two points on a trace and shorts between traces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.