| 摘要 |
PURPOSE: Provided is a composition for producing ceramic heaters, sintered at a lower temperature than conventional composition of ceramic heaters by adding Pb-based frit to metallizing paste functioning as a heating element. CONSTITUTION: The composition comprises ceramic matrix consisting of (65-95wt.%) of Al2O3 - (3-20wt.%) of SiO2 - (1-10wt.%) of ZrO2 - (1-5wt.%) of MgO and metallizing paste consisting of (90-99.5wt.%) of tungsten, W - (0.5-10wt.%) of Pb-based frit which is composed of (55-85wt.%) of PbO - (2.5-15wt.%) of B2O3 - (10-15wt.%) of SiO2 - (2.5-10wt.%) of Al2O3 - (0-5wt.%) of Na2O. The ceramic heaters are manufactured by the following steps of: mixing ceramic matrix composition, solvent, dispersant and plasticizer to prepare alumina slurry with 15000-24000cps of viscosity; forming the mixture into a green sheet shape with 0.5-2mm in thickness by doctor blade method or forming it into a tube or rod shape by extruding prepared green sheets; preparing W-paste; printing metal patterns on the alumina sheet with W-paste through silk screening; hot pressing printed green sheet and alumina green sheet at 80deg.C under pressure of 100kg/cm¬2 for plate-shaped ceramic heaters, wherein the tube or rod-shaped ceramic heaters are also manufactured by layering metal-printed alumina sheets to the tube or rod-shaped ceramic heaters; and sintering it at 1250-1550deg.C.
|
