SHOWER PLATE AND METHOD FOR MANUFACTURING THE SAME

摘要

A compatible shower plate of constant quality in which a process gas blow-out hole has a simple structure and can be machined easily, the blow-out hole has dimensions of high precision and uneven blow-out of process gas and generation of particles are eliminated. Ceramic material-use power of low dielectric constant is press-formed into disc-shape having overall dimensions where sintering shrinkage and finish allowance are taken into account. In the stage of disc-like molding, a molding hole for a gas introduction passage (3) and the blow-out hole (2) is bored before sintering. Subsequently, the gas introduction passage (3) and the blow-out hole body portion (2b) are polished to provide surface roughness within 1s. A lapping wire having a tapered distal end is then inserted into an ejection opening (2a) and slid sequentially to the side of larger wire diameter while reciprocating it. Finishing work is performed to attain dimensional accuracy within ±0.002 mm and surface roughness within 1s when the diameter is in the range of 0.1-0.3 mm.