| 摘要 |
PURPOSE:To absorb the thermal expansion of a warpage-proof plate which prevent a printed substrate from being warped by application of a spring force by a method wherein the one end of the warpage-proof plate is fixed and the other end is supported freely with the spring. CONSTITUTION:A printed substrate P is placed on the predetermined positions of claws 2 and 3 and fixed firmly by pressing members 4. A carrier which holds the printed substrate as described above is made to pass through an automatic soldering machine to solder the printed substrate. At that time, the printed substrate is heated to a high temperature and its center part tends to be warped downward. However, as a warpage-proof plate 5 is provided under the printed substrate so as to touch the printed substrate, the warpage is restricted. Although the warpage-proof plate 5 itself shows thermal expansion, a pressing spring 12 attached to the rising part 8 of the warpage-proof plate 5 supports the warpage-proof plate 5 in such a manner that the expansion of the warpage-proof plate 5 caused by the thermal expansion is relieved to the lateral direction (direction of the rising part), so that the downward warpage of the warpage-proof plate 5 can be avoided. |
