JPS62221551A - Thermal head - Google Patents

Abstract

PURPOSE:To shorten the thermal response of a thermal head and at the same time, to make the handling of a lot during the manufacturing process of a substrate easy, by freshly inserting a ceramics sheet between a substrate and a radiation plate. CONSTITUTION:If a ceramics sheet 3 is freshly inserted between the substrate 1 of a thermal head and a radiation plate 4, the practical thickness of the substrate becomes not less than 2mm. As a result, the thermal response characteristics increase and at the same time, the handling of a lot during the manufacturing process of the thermal head substrate becomes easy. For the cause by which the thermal response characteristics are increased, if heat is conducted via the contact between the ceramics sheets of rough surface (large surface area), the thermal conductivity is increased by comparing it with the thermal conduction from the thermal head substrate to the radiation sheet of smooth surface and the ceramics sheet itself can be considered to function as the heat sink in high speed printing.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a thermal head.

[Conventional technology]

In a conventional thermal head, a partial glaze, a full glaze, etc. are applied as a heat storage layer on a ceramic substrate made of alumina, enamel, silicon carbide, etc., and a heating resistor and a conductor made of a thin film material or a thick film material are further applied to the substrate. A thermal head substrate is formed on the thermal head substrate, and if desired, a driving IC for driving a heating element is mounted or connected on this substrate. This thermal head substrate was fixed on a heat sink and provided the necessary functions as a thermal head.

[Problem that the invention seeks to solve]

The conventional thermal head described above generally has a thickness of 0.6
Since a single ceramic substrate with a small heat capacity of ~1.6 mm is fixed on a heat sink, when the thermal head prints at high speed, the large amount of heat generated by the heating resistor is A phenomenon occurs in which the thermal head board is heated to a high temperature, and the heated thermal head board conducts heat to the heat sink after a certain response time.
Although the temperature decreases, this response time is long in conventional thermal heads, and for example, if one line is printed and recorded in less than 271,000 seconds, the quality of the print recording deteriorates significantly, which is a problem that must be prevented. Therefore, when the thickness of the ceramic substrate is set to 2 mm or more, the weight of the ceramic becomes heavy, which has the disadvantage that loft treatment during the manufacturing line process of the thermal head substrate becomes difficult.

Means for Solving Problem C] The thermal head of the present invention is characterized in that a ceramic plate is inserted between a thermal head substrate provided with a heating resistor and a heat sink on which the substrate is mounted. shall be.

In this way, by inserting a new ceramic plate between the thermal head substrate and the heat sink, the effective thickness of the thermal head substrate becomes 20 mm or more, and as a result, the thermal response characteristics of the thermal head become faster, and the thermal head substrate Lot processing during the manufacturing process becomes easier.

It is not clear why the increase in the effective thickness of the thermal head substrate increases the thermal response characteristics of the thermal head, but compared to the heat conduction from the thermal head substrate to the smooth surface of the heat sink, the roughness of the surface (lower surface area) This is believed to be due to the high thermal conductivity conducted through the contact between the large (large) ceramic plates, and thus the ceramic plates themselves act as heat sinks during high speed printing. According to experiments, it was appropriate that the effective thickness of the ceramic plate be 2 mm or more.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view schematically showing an embodiment of the thermal head of the present invention.

A thermal head substrate 1 including a partial glaze 2 and a heating resistor is fixed onto a heat sink 4 via a newly inserted ceramic plate 3.

Further, a driving IC 5 is mounted on the thermal head substrate 1, and this driving IC 5 is driven by being supplied with an electric signal by a 7-lex cable plate 6 fixed on the heat sink 4. The top of the IC section is generally protected by a protective cover 7.

Here, it goes without saying that the material and fixing method of the ceramic plate 3 and the material and shape of the heat sink 4 should not be particularly limited. Therefore, it goes without saying that, for example, the ceramic plate 3 may be bonded to the heat dissipation plate 4 or the thermal head substrate 1 using epoxy resin, silicone resin, or the like having high thermal conductivity.

〔Effect of the invention〕

As explained above, the present invention increases the effective thickness of the thermal head substrate by inserting a new ceramic plate between the thermal head substrate and the heat sink, thereby improving the thermal response of the thermal head. This has the effect of speeding up the process and facilitating lot processing during the manufacturing process of the thermal head substrate.

[Brief explanation of drawings]

FIG. 1 is a sectional view schematically showing an embodiment of the thermal head of the present invention. l... Thermal head board, 2... Partial glaze, 3... Ceramic plate, 4... Heat dissipation plate, 5... Drive IC, 6... Flexi cable plate, 7... protective cover. M1 figure

Claims (1)

[Claims] A thermal head characterized in that a ceramic plate is inserted between a thermal head substrate provided with a heating resistor and a heat sink on which the substrate is mounted.