Abstract: In a ceramic heater having a plate-like body made of a ceramic, heating element in one main face of the plate like body, and an electric supply portion to be electrically connected with the heating element, it has been a problem that the temperature is uneven if bent portions are formed in heat generating patterns. The ceramic heater simultaneously satisfying the following: 0.15≦S≦0.85, 0.3≦P≦6.71×S2+1.52, and 0.3≦G≦6.71×(1−S)2+1.55, in which the reference character S1 denotes the surface area of the heating element in optional 10 mm square region of the effective heat generation area having the heating element therein; the surface ratio S denotes S=S1/100 mm2, the reference character P denotes the width of the heating element: and the reference character G denotes the gap between the heating element.

Abstract: A wafer heating apparatus is provided, including a heat-homogenizing plate comprising a ceramic substrate and having a mounting surface which is an upper surface of the ceramic substrate for mounting a wafer thereon, a heating element provided on the lower surface of the heat-homogenizing plate and pad electrodes connecting electrically to the heating element on said lower surface, wherein the mounting major surface is convex, particularly, with the height of the central portion of the mounting major surface with respect to the periphery thereof is in a range of 10 to 80 &mgr;m. In the wafer heating apparatus a plurality of supporting pins are planted on the mounting surface to support the wafer thereon placed from the mounting surface. The ceramic substrate includes silicon carbide, and an insulating layer is secured on the ceramic substrate and the heating element is secured on said insulating layer, the insulating layer being a glass layer having an lower expansion coefficient by 0.

Abstract: In a ceramic heater having a plate-like body made of a ceramic, heating element in one main face of the plate like body, and an electric supply portion to be electrically connected with the heating element, it has been a problem that the temperature is uneven if bent portions are formed in heat generating patterns. The ceramic heater simultaneously satisfying the following: 0.15≦S≦0.85, 0.3≦P≦6.71×S2+1.52, and 0.3≦G≦6.71×(1−S)2+1.55, in which the reference character S1 denotes the surface area of the heating element in optional 10 mm square region of the effective heat generation area having the heating element therein; the surface ratio S denotes S=S1/100 mm2, the reference character P denotes the width of the heating element and the reference character G denotes the gap between the heating element.

Abstract: A wafer heating apparatus is provided, including a heat-homogenizing plate comprising a ceramic substrate and having a mounting surface which is an upper surface of the ceramic substrate for mounting a wafer thereon, a heating element provided on the lower surface of the heat-homogenizing plate and pad electrodes connecting electrically to the heating element on said lower surface, wherein the mounting major surface is convex, particularly, with the height of the central portion of the mounting major surface with respect to the periphery thereof is in a range of 10 to 80 &mgr;m. In the wafer heating apparatus a plurality of supporting pins are planted on the mounting surface to support the wafer thereon placed from the mounting surface. The ceramic substrate includes silicon carbide, and an insulating layer is secured on the ceramic substrate and the heating element is secured on said insulating layer, the insulating layer being a glass layer having an lower expansion coefficient by 0.

Abstract: In a heating roller for fixing which is constituted such that a heating resistor 3 is provided onto an inner circumferential surface 1a of a cylinder 1 with an insulating layer 2 lying therebetween and a cleavage layer 6 is provided onto an outer circumferential surface, electrical insulating properties of the insulating layer 2 are maintained satisfactorily for a long time. A maximum height (Rmax) of surface roughness of the inner circumferential surface 1a of the cylinder 1 is in the range of 0.8 of 50 &mgr;m. A resistance value in the heating roller for fixing is partially adjusted easily. In a heating roller for fixing having a heating resistor 103 on a surface of a cylinder 101 with an insulating layer 102 lying therebetween, the heating resistor 103 is divided into a plurality of zones in an axial direction of the cylinder 101, and slots for adjusting resistance are formed in each zone.

Abstract: In a heating roller for fixing which is constituted such that a heating resistor 3 is provided onto an inner circumferential surface 1a of a cylinder 1 with an insulating layer 2 lying therebetween and a cleavage layer 6 is provided onto an outer circumferential surface, electrical insulating properties of the insulating layer 2 are maintained satisfactorily for a long time.A maximum height (Rmax) of surface roughness of the inner circumferential surface 1a of the cylinder 1 is in the range of 0.8 to 50 .mu.m.A resistance value in the heating roller for fixing is partially adjusted easily.In a heating roller for fixing having a heater resistor 103 on a surface of a cylinder 101 with an insulating layer 102 lying therebetween, the heating resistor 103 is divided into a plurality of zones in an axial direction of the cylinder 101, and slots for adjusting resistance are formed in each zone.