Abstract: An improved resistive heating device includes multiple printed heating elements joined through a flexible film substrate to bus bars printed on an opposite side of the flexible film. The heating elements may be printed using a positive temperature coefficient ink to provide a self-regulated maximum temperature based on a given input voltage. This printing of electrical components on both sides of a flexible film, referred to herein as double-sided polymer circuitry (D/SPC®), provides various additional advantages over single-sided printing, such as an increased heat per unit surface area. This also provides a more concentrated and evenly distributed heat pattern, and will reduce or eliminate the exhibition of hot spots or varying patterns of heat throughout the heating element. This printing on both sides of the flexible film results in an improved, fault-tolerant bus bar topology, which may be used in fault-critical medical applications or other mission-critical applications.

Abstract: An improved resistive heating device includes multiple printed heating elements joined through a flexible film substrate to bus bars printed on an opposite side of the flexible film. The heating elements may be printed using a positive temperature coefficient ink to provide a self-regulated maximum temperature based on a given input voltage. This printing of electrical components on both sides of a flexible film, referred to herein as double-sided polymer circuitry (D/SPC®), provides various additional advantages over single-sided printing, such as an increased heat per unit surface area. This also provides a more concentrated and evenly distributed heat pattern, and will reduce or eliminate the exhibition of hot spots or varying patterns of heat throughout the heating element. This printing on both sides of the flexible film results in an improved, fault-tolerant bus bar topology, which may be used in fault-critical medical applications or other mission-critical applications.