| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-durability device by providing a heating section and lead sections on a heating resistor arranged on a ceramic substrate, and setting the electric resistance of the heating section in the range of a specific range against the total electric resistance 100% of the heating section and the lead sections at the ordinary temperature. SOLUTION: The electric resistance of a heating section 21 is set to 55-80% against the total electric resistance 100% of the heating section 21 and lead sections 23a, 23b. When the lead sections 23a, 23b are changed in shape to increase the electric resistance, the electric resistance of the heating section 21 can be set to 55-80%. For changing the lead sections 23a, 23b in shape to increase the electric resistance, slits are provided on the lead sections 23a, 23b to decrease the cross sectional areas in which a current flows. When the electric resistance of the lead sections 23a, 23b is increased, the ratio of the electric resistance of the heating section 21 is decreased, and the durability of the heating section 21 is improved. |
