Patent ID: 6664515
Filing Date: 2003-12-16
Classification: H01L,H05B

Abstract:
A circuit pattern of resistance heating elements embedded in an insulating substrate having a defined periphery, the circuit pattern comprising:at least one current-receiving point provided at a central portion of the insulating substrate; at least one current-releasing point provided at the central portion of the insulating substrate; one or more resistance-heating-element circuits that: have one of a spiral form and a pseudospiral form; are formed from the central portion including the current-receiving point to the peripheral portion of the insulating substrate; and one or more resistance-heating-element circuits that: have one of a spiral form and a pseudo spiral form; and are formed from the outermost portion of the resistance-heating-element circuits to the central portion including the current-releasing point; and wherein the spiral or pseudospiral resistance-heating-element circuit formations merge with one another at the peripheral portion of the substrate.