"Method for particle beam testing of substrates for liquid crystal displays ""LCD"""

US5268638A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Matthias Brunner · Tauberbischofsheim, DE
• Reinhold Schmitt · Munich, DE

Key dates

• Filing date: May 13, 1992
• Grant date: Dec 7, 1993
• Expiry date: May 13, 2012

Classification

• Technology area (CPC G): Physics
• CPC primary: G02F1/136254
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Method for particle beam testing of substrates for liquid crystal displays (LCD). This invention is directed to methods wherein, given a substrate (SUB1) for a liquid crystal display, either potentials or, respectively, currents are set in defined fashion with a particle beam (S1, S2 and S4) and/or potentials are measured by detecting secondary electrons (S5) at different switch statuses of the switch elements (T) of the substrate (SUB1). The geometrical integrity and the electrical functionability of the substrate (SUB1) are thereby tested, even though, for example, a supplementary plane electrode is not present for forming a capacitor. An important advantage of the method is that faulty substrates can be repaired or can be segregated even before further-processing and, thus, costs can be reduced.