Abstract: A planar light source having a first substrate, a plurality of electrode modules, a second substrate, a dielectric spacer, a first phosphor layer, and a discharge gas is provided. The electrode modules are disposed on the first substrate. The second substrate is disposed above the first substrate. The dielectric spacer covers the electrode modules and is connected between the first substrate and the second substrate. The space between the first substrate and the second substrate is divided into a plurality of discharge spaces by the dielectric spacer. The first phosphor layer is disposed in the discharge spaces. The discharge gas is disposed in the discharge spaces. The coating area of the phosphor layer can be increased and cracks in the substrate can be prevented due to the simple structure of the planar light source.

Abstract: In an epoxy resin composition comprising an epoxy resin, a curing agent, and at least 70% by weight of an inorganic filler, at least one of the epoxy resin and the curing agent has such a molecular weight distribution as to provide an average dispersity Mw/Mn of less than 1.6, a two-nucleus compound content of less than 8% by weight and a seven- and more-nucleus compound content of less than 32% by weight. When the composition is cured at 180.degree. C. for 90 seconds into a primary product having Tg1 and the primary product postcured at 180.degree. C. for 5 hours into a secondary product having Tg2, the relationship: (Tg2-Tg1)/Tg2<0.1 is satisfied. The composition is fast-curing and effectively moldable and cures into a reliable product without a need for postcure.