Operational PDP fabrication by using a fully vacuum in-line sealing technology

Improper base vacuum level in any vacuum microelectronic device, such as a plasma display panel (PDP) or a field emission display (FED), will damage t he overall performance of the device due to impurities such as H-2, O-2, CO , CO2, and N-2. In conventional tubulation packaging technology, the obtain able base vacuum level before plasma gas filling will be very poor because of the a pumping conductance limitation for such a large panel size with a small gap of 150 mu m, especially due to the barrier ribs inside the PDP pa nel. The time required to reach any reasonable level will be too long. In t his study, by sealing the two glass plates composing the PDP panel, we perf ormed a plasma gas filling into the panel and a hole-off (named instead of a conventional 'tip-off') process, called as 'vacuum in-line sealing', in a vacuum chamber. Several factors related with the heating process of a frit glass were investigated. A prepared frit glass was successfully applied fo r the vacuum inline sealing approach without suffering bubbles. We successf ully fabricated an operable PDP panel with a a-inch diagonal size by using the fully vacuum in-line sealing technology for the first time in the world . The sealing temperature of the two plates was around 330 degrees C which corresponded to a temperature about 120 degrees C lower than that used in a conventional air environment. The base vacuum level inside the panel befor e gas filling was about 5 x 10(-6) Torr at the time of sealing. Then, a Ne- Xe (4 %) mixture gas was introduced into the panel-inside through a tubeles s hole in the glass plate until 400 Torr. Subsequently, the 'hole-off' proc ess was done by using hit sealing in the vacuum chamber. The hole-off time was negligible. Thus, the total elapsed time for the sealing processes was less than 6 hours, including the gas fill and the hole-off processes. The p anel was successfully operated with a starting voltage of 190 V driven by 5 0-kHz AC mode, giving a sufficiently high and uniform brightness for all th e pixels.