| 摘要 |
<p>PURPOSE:To reduce dimensional shrinkages of a flexible board by eliminating residual stress, resulting from manufacturing processes of the board, by means of heating processes. CONSTITUTION:A conductive foil 2 used for forming a circuit pattern 6 is laid over a flexible board 5, and the laminated structure is then wrapped in a coil with the conductive foil 2 side thereof being enclosed, wherein the diameter of the coil is in a range of 25mm-50mm. The coiled board is then subjected to heating processes at a temperature of 100-200 deg.C for half an hour - three hours. Heating processes with a much lower temperature do not effectively cause residual stress to be eliminated, whilst the heating processes with a much higher temperature causes a base material of a film and an epoxy adhesive to be thermally deteriorated. Therefore, the temperature of the heating processes is strictly limited to the range of 100-200 deg.C. Thereby, the residual stress accumulated in the flexible board 5 is eliminated, and hence thermal shrinkages of the board can be reduced.</p> |
