| 摘要 |
PROBLEM TO BE SOLVED: To provide the subject jig equipped with plate-like shelf boards of crystallized glass each having flat surface to put a to-be-heat-treated object on and also with supports for piling use made of crystallized glass and vertically fittedly inserted through penetrating holes formed near the respective four corners of the shelf boards and then jointed firmly, so as to retain high flatness over a long time with no pores inside the shelf boards and the supports, generate no impurity gas during temperature rise, and properly correct the warpage of thin glass plates as the objects. SOLUTION: In this jig, the thermal expansion coefficient of the crystallized glass is <=15×10<-7> / deg.C. The figure shown is a magnified sectional view of this jig. Each of shelf boards 1a is provided with penetrating holes 4 near the four corners. Each of supports 2 is a means for piling the shelf boards 1, serving to hold the shelf boards 1 at their respective given positions and fully prevail the atmospheric temperature throughout the mutual gaps of the shelf boards 1. Each of the inserts through the penetrating holes 4, which is of rod shape 10-20mm in the whole length, is fittedly inserted vertically through the penetrating hole 4 and then weldedly fixed at 910-950 deg.C, thus affording a joint strength of 60kgf/cm<2> .
|
