Thick film heater apparatus
AssigneeHusky Injection Molding Systems Ltd.
InventorsAndrew Booth, Harold Warren, Wink Winkelmann, Edward Jenko, Jim Pilavdzic
Life of this patent
Estimating the term…
Abstract
A thick-film electric heater having thick-film layers applied directly on a thermally conductive non-flat substrate. Preferably, the substrate is cylindrically shaped. A dielectric layer is silk-screened on the substrate surface. A resistive layer is silk-screened on the dielectric layer to form a circuit for the generation of heat. The resistive layer has at least one resistive trace in a pattern that is discontinuous circumferentially. At least a pair of silk-screened contact pads are applied in electrical communication with the resistive layer for electrical connection to a power source. An insulation layer is applied over the resistive layer.
Claims25
A thick-film electric heater, comprising:
- a) a thermally conductive non-flat substrate surface;
- b) a silk-screened dielectric layer applied on said substrate surface;
- c) a resistive layer applied on said dielectric layer thereby forming a circuit for the generation of heat, the resistive layer having at least one resistive trace made of thick film ink in a pattern that is discontinuous circumferentially;
- d) at least a pair of silk-screened contact pads applied in electrical communication with said resistive layer for electrical connection to a power source;
- e) an insulation layer applied over said resistive layer;
- and
- f) wherein the thermally conductive non-flat substrate surface has a thermal coefficient of expansion substantially the same or slightly lower than the dielectric and resistive layers.
An injection mold runner nozzle having a co-axially disposed cylindrical heater comprising:
- a) a cylindrical, thermally conductive substrate having a smaller coefficient of thermal expansion than that of said nozzle, thereby causing said substrate to clamp onto said nozzle as said nozzle and said substrate heat up;
- b) a dielectric layer applied on said substrate;
- c) a resistive layer applied on said dielectric layer thereby forming an electrical circuit for heat generation, the resistive layer having at least one resistive trace made of thick film ink in a pattern that is discontinuous circumferentially around the substrate;
- d) at least a pair of contact pads applied in electrical communication with said resistive layer for electrical connection to a power source;
- e) an insulation layer applied over said resistive layer and
- f) wherein the cylindrical, thermally conductive substrate has a thermal coefficient of expansion substantially the same or slightly lower than the dielectric and resistive layers.
A thick-film electric heater, comprising:
- a) a thermally conductive non-flat substrate surface;
- b) a dielectric layer applied on said substrate surface;
- c) a resistive layer applied on said dielectric layer thereby forming a circuit for the generation of heat, the resistive layer having at least one resistive trace made of thick film ink in a pattern that is discontinuous circumferentially;
- d) at least a pair of contact pads applied in electrical communication with said resistive layer for electrical connection to a power source;
- e) an insulation layer applied over said resistive layer;
- and
- f) wherein the thermally conductive non-flat substrate surface has a thermal coefficient of expansion substantially the same or slightly lower than the dielectric and resistive layers.
Dependencies are inferred from the claim text.