JPS5921309B2 - fever recording element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat generating recording element of a heat generating recording device, particularly to a structure of a wide heat generating recording element.

Conventionally, when manufacturing a heat-generating recording element having a width of 50 mm or more, a single alumina ceramic plate is used as a substrate, and heat-generating elements are arranged continuously on the board at once, or multiple sheets are arranged. A wide range of heat-generating recording elements were manufactured by gluing an alumina ceramic plate onto an aluminum plate. However, large alumina ceramic plates are difficult to manufacture and have low yields, making them expensive. On the other hand, when a plurality of alumina ceramic plates are bonded onto an aluminum plate, the alumina ceramic plate is rapidly heated or cooled by the operation of the heating element. As mentioned above, alumina ceramic substrates are exposed to severe heat shock, and due to the difference in thermal expansion coefficients between aluminum and alumina, the connection parts are subjected to large stress and often break.

The present invention provides a heat-generating recording element that is not damaged by temperature changes by bonding an alumina ceramic substrate onto a Kovar alloy plate having a specific composition and having a coefficient of thermal expansion comparable to that of the alumina ceramic substrate. The purpose is to

By setting the composition of the Kovar alloy plate whose main components are 50 to 90% Fe, 40 to 5% Ni, and 10 to 1% CO, in terms of weight percent, Ni 29.5 ± 5%, Co 16 ± 3%, and the remainder is Fe. Its thermal expansion coefficient is 5.2~5.4×1
0-6/°C, and the coefficient of thermal expansion can be made almost the same as that of the alumina ceramic substrate used.

Therefore, a continuous wide heat-generating recording element constructed by connecting a plurality of heat-generating recording elements on which a plurality of alumina ceramic plates are butt-connected and bonded to each other on this Kovar alloy plate is a heat-generating recording element. The connections will not be stressed by shocks. An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing the structure of two heat-generating recording elements constituting an embodiment of the invention, FIG. 2 is a plan view of a Kovar alloy plate according to the invention, and FIG. 3 is an embodiment of the invention. FIG. 3 is a plan view and a vertical cross-sectional view showing an example. In the figure, 1 is a heating element lead, 2 is a heating element, 3 is an alumina ceramic plate,
4 is a Kovar alloy plate, 5 is an adhesive, and 6 is a butting surface. As shown in FIG. 1, the heating recording element has an alumina ceramic plate 3 as a substrate, and heating elements 2 arranged in a line on the surface thereof. The Kovar alloy plate 4 is a plate of 0.1 to 511 m made of the above-mentioned components and has almost the same coefficient of thermal expansion as the alumina ceramic plate 3.

As shown in FIG. 3, one embodiment of the present invention is such that two heat-generating recording elements are bonded together on a Kovar alloy plate 4 at their abutting surfaces 6 using an epoxy adhesive or other heat-resistant adhesive. The Kovar alloy plate 4 and the alumina ceramic plate 3 remain intact even when subjected to heat shock.
Since the coefficient of thermal expansion is almost the same, no distortion occurs on the abutting surfaces. Therefore, it is possible to obtain a wide range of heat-generating recording elements that are less likely to fail due to heat shock. In particular, although Kovar alloy was used in this invention,
The reason for using Kovar alloy is not only that it is economical (that is, cheap), but also that there is no extreme difference in weight from the aluminum plate conventionally used as a heat-generating recording element, and that it is possible to change the composition. Therefore, the coefficient of thermal expansion is comparable to that of the alumina ceramic substrate (i.e., 5.
2 to 5.4×10 −6 /° C.).

As explained above, in this invention, an alumina ceramic substrate is bonded onto a Kovar alloy plate of a specific composition having a coefficient of thermal expansion comparable to that of the alumina ceramic substrate, so that a heat-generating recording element that is not damaged by temperature changes can be created. This has the effect that a wide heating element can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the structure of two heat-generating recording elements constituting an embodiment of the invention, FIG. 2 is a plan view of a Kovar alloy plate according to the invention, and FIG. 3 is an embodiment of the invention. FIG. 3 is a plan view and a vertical cross-sectional view showing an example. In the figure, 2 is a heating element, 3 is an alumina ceramic plate,
4 is a Kovar alloy plate, 5 is an adhesive, and 6 is a butt surface.

Claims (1)

[Claims] 1. In a heat generation recording element of a heat generation recording device having an alumina ceramic plate as a substrate and heat generation elements arranged in a line on the alumina ceramic plate, a plurality of sheets of alumina ceramic each having a heat generation element arranged in a line as described above are used. The plate was made of Ni29.5±5%, Co16 in weight%.
A heat-generating recording element characterized in that it is bonded to a Kovar alloy plate having a composition of ±3% and the remainder being Fe at positions where they abut against each other.