MULTI POLYMER POSITIVE TEMPERATURE COEFFICIENT HEATER
FIG2 is a cross-sectional view of the PTC heating element showing additional layers
Referring to FIG2, bus bars 12, polymer inks/layers 14 and 16 are disposed between dielectric layer 20 and adhesive layer 22. A second dielectric layer 20 is disposed on a side of adhesive layer opposite bus bars 12, polymer inks/layers 14 and 16. Each dielectric layer 20 can be formed from a polymer material, and can be arranged as a film, or one or more sheets or plies. An exemplary polymer can include a polyimide, such as Kapton®, because of its dielectric and non-flammable properties. Other suitable polymers having robust dielectric, mechanical, and thermal properties are contemplated herein. Adhesive layer 22 can help secure the other components of heating element 10, and can be formed generally from a thermally conductive, commercially available adhesive.
cross-sectional view
14
polymer inks polymer ink
12
bus bars bus bar
22
adhesive layer
18
power source
20
dielectric layer dielectric layers
16
polymer inks polymer ink
10
element
['1. A heating element comprising: a first bus bar (12) disposed to receive current from a power source; a second bus bar (12) non-adjacent to the first bus bar; and a polymer ink section extending between the first and second bus bars, the section comprising a plurality of PTC polymer inks (14,16) each different from one another; wherein the second bus bar is electrically connected to the first bus bar via the polymer ink section.']