Cold cathode fluorescent lamp, electrode unit and their manufacturing method

Abstract

The present invention comprises: a glass tube in which at least noble gas and mercury gas are enclosed in the internal space sealed airtightly and a phosphor layer is formed on the inner wall; a pair of cylindrical electrodes each of which has a bottom part on one end and an opening on the other end and placed so that the openings are opposed to each other in the internal space; and lead lines of which one ends are joined to the bottom parts and the other ends are led out to the outside of the glass tube. The cylindrical electrode is composed of a metal material made by heating nickel-based metal in which magnesium is dispersed to oxidize the dispersed magnesium.

Description

technical field [0001] The present invention relates to a cold cathode fluorescent lamp and an electrode unit constituting a part of the cold cathode fluorescent lamp, and in particular to improvements in electrode materials. Background technique [0002] Cold-cathode fluorescent lamps have the characteristics of easy miniaturization, low power consumption, and long life. In recent years, they have been widely used as backlights for liquid crystal panels. Generally, a cold cathode fluorescent lamp has a structure in which a pair of electrodes are arranged facing each other inside a glass tube filled with a rare gas such as argon and mercury gas, and a lead wire is connected to each electrode. The electrodes are formed in a cup shape and arranged such that openings of the cups face each other. When a voltage is applied between the electrodes through the leads, electrons are emitted from one electrode, hitting mercury atoms and generating ultraviolet rays. The ultraviolet ra...

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Problems solved by technology

Once the surface of the electrode is oxidized, its sputtering resistance will be significantly reduced, so the hard-won sputtering resistance will not be effective

Moreover, once molybdenum or niobium is oxidized, it is difficult to reduce it, so it is difficult to reduce it with hydrogen or the like in the subsequent process.

[0007] Second, since molybdenum or niobium are metals with high melting points, sufficient bonding strength cannot be obtained without applying very high heat when welding the lead wire to the electrode

Copper plays the role of a heat dissipation unit that dissipates the heat emitted by the electrodes to the outside of the glass tube when the lamp is in use. If the copper flows out, a cavity that is not filled with copper will be created inside the outer tube made of Kovar. part, resulting in reduced thermal performance

[0008] Third, not only is molybdenum or niobium expensive in general, but also the rolling process to make it into a thin plate or the stamping process to make it into a cup electrode is difficult and expensive

Therefore, electrodes made of these high-melting point metals are more likely to incur cost increases compared to electrodes made of nickel

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