| 摘要 |
<p>PURPOSE:To attain thermal contraction free from bubbles by arranging a single heating body adhered closely to a board on the approximately center part of a heating area of a thermal contraction tube so that heat on both the end parts of the heating body is dispersed in the direction of the board and the temperature of the center part of the heating body is higher than that on both the side parts of the temperature. CONSTITUTION:When current supply to a heater 12 is started after setting up the thermal contraction tube 15 between side plates 13, the heater 12 is uniformly heated. Since both the end parts of the board 11 are cooled, heat on both the ends of the heater 12 starts to be transmitted and dispersed. Although the temperature on the center part of the heater 12 reaches a set temperature, both the ends of the board 11 is not yet heated sufficiently and the temperature on both the ends of the heater 12 is still low. Although the temperature on both the ends of the heater 12 tries to reach the setting temperature of the heater 12, said temperature reaches steady temperature distribution at a temperature lower than the set temperature due to heat radiation from both the ends of the board 11 into air. Since temperature distribution in the width direction is uniform in respective points of the longitudinal direction, it is unnecessary to consider heating processing a the formation of temperature distribution in the longitudinal direction.</p> |
