Heater plate with embedded hyper-conductive thermal diffusion layer for increased temperature rating and uniformity

[0009]With reference to FIG. 1, a heater 11 has a critical heating surface on a thermally conductive upper plate 13. Two electrodes 19 and 21 for in internal heater coil are seen to emerge from a side of the heater 11, along with a ground electrode 20 for the plate 13.

[0010]As seen in FIG. 2, the heater 11 includes upper and lower plates 13 and 15, together with and a thermal pyrolytic graphite (TPG) diffusion layer 17 and an electrically isolated heating element 23 located between the two plates 13 and 15. An interface material, not shown, fills voids between the various component parts 13, 15, 17 and 21, and bonds the plates 13 and 15 together.

[0011]The upper and lower plates 13 and 15 may be made of metal. However, the plate material need not have especially high thermal conductivity in the plane of the plates because of the presence of the TPG diffusion layer 17 that serves to uniformly spread the heat from the heating element across the critical surface of the upper plate 13. Thus