Layered heater system having conductive overlays
AssigneeWatlow Electric Manufacturing Company
InventorsElias Russegger, Gerhard Schefbanker, Martin Wallinger, Kevin Ptasienski
Life of this patent
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Abstract
A layered heater includes a resistive layer defining a resistive circuit pattern having at least one bend portion. A conductive overlay is provided on at least one of a top surface and a bottom surface of the bend portion to alleviate the current crowding effect, thereby protecting the electric circuit from premature failure. Methods of manufacturing the layered heater are also disclosed. The overlay may be formed on the bend portion after the resistive layer is formed. The overlay may also be formed on a substrate or a dielectric layer that supports the resistive layer before the resistive layer is formed.
Claims22
A layered heater comprising:
- a substrate;
- a dielectric layer formed on the substrate;
- a continuous resistive layer formed on the dielectric layer, the continuous resistive layer comprising a conductive material separated into an intermediate area and a resistive circuit pattern by a plurality of cuts that extend all the way through the continuous resistive layer, the resistive circuit pattern having at least one bend portion, the bend portion having a top surface and a bottom surface;
- termination pads electrically connected to the resistive circuit pattern;
- the intermediate area being electrically inactive;
- a conductive overlay disposed on at least one of the top surface and the bottom surface of the bend portion;
- wherein the plurality of cuts extend longitudinally into the conductive overlay such that no portion of the resistive pattern is present outside the conductive overlay or the plurality of cuts do not extend longitudinally into the conductive overlay such that the intermediate area does not come into electrical contact with the conductive overlay;
- and
- a second dielectric layer formed over the resistive layer and the conductive overlay.
A layered heater comprising a resistive layer formed from a conductive material and separated into an intermediate area and a resistive circuit pattern by a plurality of cuts that extend all the way through the resistive layer, the resistive circuit pattern including termination pads electrically connected to the resistive circuit pattern with the intermediate area being electrically inactive, and a conductive overlay disposed over a continuous portion of the resistive circuit pattern;
- wherein the plurality of cuts extend longitudinally into the conductive overlay such that no portion of the resistive pattern is present outside the conductive overlay or the plurality of cuts do not extend longitudinally into the conductive overlay such that the intermediate area does not come into electrical contact with the conductive overlay.
A layered heater comprising:
- a substrate;
- a first dielectric layer formed on the substrate;
- a continuous resistive layer formed on the dielectric layer, the continuous resistive layer comprising a conductive material separated into an intermediate area and a resistive circuit pattern by a plurality of cuts that extend all the way through the continuous resistive layer, the resistive circuit pattern having at least one bend portion and at least one straight portion;
- termination pads electrically connected to the resistive circuit pattern;
- the intermediate area being electrically inactive;
- a plurality of conductive overlays disposed on at least one of the bend portion and the straight portion;
- wherein either the plurality of cuts does not extend longitudinally into the plurality of conductive overlays such that the intermediate area does not come into electrical contact with the conductive overlays or the plurality of cuts extend longitudinally into the plurality of conductive overlays such that no portion of the resistive pattern is present outside the conductive overlays;
- and
- a second dielectric layer formed over the resistive layer and the plurality of conductive overlays.
Dependencies are inferred from the claim text.