JPS58128871A - Thermal head - Google Patents

Abstract

PURPOSE:To provide a thermal head of stable performance, free from break off and crack in its cut surface by such an arrangement wherein on an insulation substrate, a heat generating element and an electrode and a wear resistive layer for protecting them are provided, and a substance of which adhesiveness is poor is coated on the part of cutting in advance. CONSTITUTION:A glass glaze layer 2 for accumulating heat is provided on an insulation substrate 1, and thereon a heat generating resistor 3, an electrode 4, an oxidation prevention film 5 for preventing thermal oxidation of the heat generating element 3 and a wear resistive layer 6 for protecting those layers are provided, and in the thermal head composed as above, a breakable film 10 wherein a substance of which adhesiveness is poor is coated in advance is provided at the part of cutting. The oxidation prevention film 5 and the wear resistive layer 6 formed on the breakable film 10 are very brittle, therefore, in cutting the head by the blade 9 of a dieing machine, it can be cut without causing tipping phenomenon and generating breakoff and crack.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal head that facilitates division and cutting of the thermal head, which is composed of a heating element, a shield, an electrode, and a wear layer that protects them on an insulating substrate.

Conventionally, when multiple thermal heads are formed on a single insulating substrate, the substrate cutting method is to form the desired film with snap lines on the insulating substrate, and then divide the thermal head once it is completed. Two methods have been used: one method involves cutting and dividing using a dicing device. However, this cutting and dividing method does not pose a big problem when manufacturing serial heads, but when manufacturing line heads,
This becomes a major drawback when the heating resistor is located near the end face of the insulating substrate.

In other words, the abrasion-resistant layer, which plays a role in preventing abrasion with the thermal recording paper, is extremely hard, which causes a chipping phenomenon on the cut surface, resulting in chipping as shown in Figure 1. It appears as crack 9. In the worst case, these chips 8 and cracks 9 extend to the vicinity of the heating resistor 5.

In the special KiIIk vicinity, there is a technology that drives the thermal head at higher speed)l! However, in order to achieve this, it is necessary to shorten the pulse width applied to the head and increase the head temperature, causing the head to heat up.

A major drawback is that the slight rack that occurs at the cut surface when cooled progresses due to thermal stress, significantly reducing the performance of the head.

The present invention has been devised to eliminate the above-mentioned drawbacks, and provides a thermal head with stable quality and performance in cutting by devising a cutting section.

The present invention will be described in detail below with reference to the drawings.

5 is a schematic cross-sectional view of the structure of a thermal head showing an embodiment of the present invention. 1 is an insulating substrate made of a good thermal conductor, and Almana ceramic is usually used. 2 is a glass glaze layer formed on the insulating substrate 1. This glaze layer 2 has the role of storing the heat generated by the heating resistor 5, and has the overlapping role of changing the heat balance by controlling this glaze layer. 4
Thickness is 1 to 1 with wire electrode.
It is 5 μm. It is an anti-oxidation film that acts as a round oxygen cutoff to prevent thermal oxidation of the heating element 5, and 8102 or the like is used. 6 is an abrasion-resistant layer for preventing abrasion and deterioration of the rolls that come into contact with the thermal recording paper;
Such as OI! A thick film is used and a thickness of 4 to 6 μm is required. No. 10 indicates damage that impairs adhesion to the thin film, which is the key point of the present invention. In this example, oil-based paint was used. When a film is formed on this ruptured film 10 using a sputtering device, the ruptured film 1110 itself will not peel off due to the influence of the sputtering heat, and the oxidation preventive film formed thereon [11, wear-resistant layer] No. 12 is laminated even in the trenches where the adhesion is insufficient.

Therefore, the membrane formed on the ruptured membrane 10 is a very fragile membrane. 9 is a dicing blade (a stone);
It is for cutting and dividing.

When cutting with this blade 9, the sputtered film 11.11
Since the material No. 2 has very poor adhesion and is brittle, it has become possible to cut the material without causing the chipping phenomenon as shown in FIGS. 1 and 2.

Figure sI4 shows the cut surface after cutting, but the anti-oxidation film 11 and wear-resistant layer 12 left behind on the cut surface can be easily removed by ultrasonic cleaning, and the cut surface has a slim shape. This is particularly effective in improving reliability in a line head in which the heating resistor is located near the end surface of the insulating substrate.

As described above, according to the present invention, when a plurality of line heads are separated from one insulating substrate, the cut surface is sharp, so it is possible to achieve high reliability and long life without being adversely affected by the external environment. It provides a thermal head.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional thermal head in a cut state. FIG. 2 is a sectional view after cutting and dividing. FIG. 3 is a cross-sectional view of an embodiment of the present invention, and FIG. 4 is a cross-sectional view after division. 1... Insulating substrate 2... Glaze 3...
Heat generating resistor 5... anti-quantification film 4... electrode
7...Crack part 8...Crank
? ...Blade 10...Coating 11.
... Anti-aging film 12 ... Wear-resistant layer 6 ...
Umbrella wear-resistant layer or higher Answer 1 Figure 7 No. 3 /

Claims (1)

[Claims] A thermal head consisting of a heating element and electrodes on an insulating substrate, and a wear layer for protecting them, characterized in that the cutting part is coated in advance with a substance with poor adhesion.