| 摘要 |
<p>PURPOSE:To form a membrane easily and stably by holding a back-etching inner reservoir filled with etching solution with at least a part of it being soaked in a liquid. temperature maintaining outer reservoir filled with medium for maintaining liquid temperature. CONSTITUTION:A back-etching inner reservoir 7 is soaked into temperature maintaining solution 17 in a liquid temperature maintaining outer reservoir 9. The liquid temperature of etching solution 18 is maintained so that etching may not be inhomogeneous in a plane to perform stable etching. The temperature maintaining solution 17 is put into the liquid temperature maintaining outer reservoir 9 to an approximately same height as the etching solution, so that pressures of the etching solution 18 and the temperature maintaining solution 17 are approximately balanced at a part of a leakage preventing packing 5. Thus leakage of the etching solution 18 is reduced, and leakage solution if any may diffuse into the temperature maintaining solution 17 to give little influence to a pattern face 4. Thus homogeneity in etching speed can be maintained, thereby preventing a problem such as breakage of a membrane.</p> |
