| 摘要 |
PURPOSE:To reduce the production cost by arranging through holes on flat surfaces extended along the longitudinal direction of the circumference of the tubes. CONSTITUTION:A part of the upper surface of tube 3 with a circular sectional form is machined in a flat plane to make the substrate transportation surface 3a, and gas ejecting holes 3b are provided on the transportation surface 3a, and plural number of the tubes 3 are supported by suspension bars 4 and a base 5. Such tubes can be manufactured at a low cost, through, for example, cold drawing method. |
