| 摘要 |
PROBLEM TO BE SOLVED: To provide a planar heating element which causes a resistor to heat uniformly.SOLUTION: The planar heating element includes an electrical insulating board 2, an electrode 3 composed of a pair of main electrodes 3a and 3b formed by printing to be opposite to each other on the electrical insulating board 2 and connection electrodes 3c and 3d branching in a comb shape from the main electrodes 3a and 3b, and the polymeric resistor 9 printed to be overlaid on the connection electrodes 3c and 3d. At least the shape of edge portions of the connection electrodes 3c and 3d covered with the polymeric resistor 9 are determined to be an almost sloped surface. When a polymeric resistor ink is printed to cover the connection electrodes 3c and 3d to make up the polymeric resistor 9, therefore, crack formation on the polymeric resistor ink is prevented. |
