Thermal head

Abstract

The invention provides a thermal head that can easily solve problems such as handling and warpage of a substrate during manufacture, has large the degree of freedom in designing a substrate, and can effectively achieve power saving. The thermal head may include a three-layer structure that includes a heat insulating layer on which heating elements may be formed, a heat radiating layer that may be provided under the heat insulating layer, and a heat storing layer that may be provided under the heat radiating layer, especially, each of the heat insulating layer and the heat storing layer may be a glass layer that is made of the same material formed by high-temperature firing.

Description

technical field [0001] The present invention relates to a thermal head using a low thermal diffusivity glass layer. Background technique [0002] It has been used historically, such as image 3 As shown, a double-layer structure thermal head in which a glass layer is formed as a heat storage layer on the upper surface of a ceramic substrate composed of alumina ceramics or the like, or as Figure 4 As shown, a thermal head composed of a single glass layer (for example, refer to Patent Document 1 and Patent Document 2). [0003] Patent Document 1: (Japanese) Unexamined Patent Publication No. 2004-50712 [0004] Patent Document 2: (Japanese) Unexamined Patent Publication No. 02-200452 [0005] The glass layer of the above-mentioned double-layer structure thermal head is formed by printing a paste-like glaze material on the upper surface of the ceramic substrate and then sintering at a high temperature. However, the thermal expansion coefficient of the material of the ceramic...

AI Technical Summary

Problems solved by technology

However, the thermal expansion coefficient of the material of the ceramic substrate and the glaze material of the glass layer are different, so there have been problems such as warping of the glass substrate after high-temperature sintering or cracks at the lamination interface.

Therefore, in order to solve the above-mentioned problems such as warping, methods such as adjusting the thickness of the glass layer or the ceramic substrate, the aspect ratio of the substrate, and the area ratio have been adopted, but the above-mentioned adjustment is also very difficult.

[0006] Moreover, in order to obtain good printing characteristics for a thermal head with a single-layer glass layer structure, its thickness should preferably be below 0.5 mm. However, such a thin thermal head has a disadvantage that it is easy to produce a thin film during the processing of the manufacturing process. broken and difficult to handle

In order to solve the above problems, a method of thickening the glass layer has been studied, but another problem has arisen, that is, deterioration of printing characteristics such as so-called ink streaks due to excessive heat storage of the thermal head.

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