HEATING DEVICE

Abstract

A heating device includes a high-frequency electrode embedded substantially in parallel with a heating surface of a ceramics base in the vicinity of the heating surface. A conducting hole toward this high-frequency electrode is formed in a back face of the ceramics base. This high-frequency electrode has a trapezoidal cone-like concave section toward the conducting hole at a region opposed to the conducting hole.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and further objects, features and advantages of the invention will more fully appear in the detailed description of embodiments of the invention, when the same is read in conjunction with the drawings, in which:

FIG. 1 is a cross-sectional view illustrating the main part of a heating device according to one illustrative embodiment of the present invention;

FIG. 2 is a cross-sectional view illustrating the main part of a heating device according to another illustrative embodiment of the present invention;

FIG. 3 is a cross-sectional view illustrating the main part of a conventional heating device;

FIG. 4 is a cross-sectional view illustrating the main part of a conventional heating device; and

FIG. 5A is a cross-sectional view illustrating a press working of a high-frequency electrode;

FIG. 5B is a cross-sectional view illustrating a press working of a high-frequency electrode.

Claims

1. A heating device including a high-frequency electrode that is embedded in a ceramics base having a heating surface for heating a to-be-heated object and that is disposed substantially in parallel with the heating surface in which a conducting hole toward this high-frequency electrode is provided at a back face of the ceramics base, wherein:the high-frequency electrode has a trapezoidal cone-like concave section toward the conducting hole at a region opposed to the conducting hole.

2. The heating device according to claim 1, wherein a distance between a part other than the trapezoidal cone-like concave section of the high-frequency electrode and the heating surface is 1.2 mm or less.

3. The heating device according to claim 1, wherein the trapezoidal cone-like concave section has a bottom face having a diameter or 3 mm or more and 5 mm or less, the concave section has a depth of 1 mm or more and 3 mm or less, the concave section has the maximum diameter of 7 mm or less, and the concave section has a side wall having an inclination angle larger than 30° and smaller than 75°.

4. The heating device according to claim 2, wherein the trapezoidal cone-like concave section has a bottom face having a diameter or 3 mm or more and 5 mm or less, the concave section has a depth of 1 mm or more and 3 mm or less, the concave section has the maximum diameter of 7 mm or less, and the concave section has a side wall having an inclination angle larger than 30° and smaller than 75°.