JP2578140B2 - Manufacturing method of thermal head - Google Patents

Description

The present invention relates to a method of manufacturing a thermal head having a head chip having an end notch.

(B) Conventional technology In general, in the case of a serial thermal head, the end shape of a head chip greatly affects print quality. That is,
In the case of a break from the wafer to individual head chips, the end shape is very sharp and sharp, with the corners damaging the paper or transfer ribbon. The conventional thermal head is provided with a notch 8 at the end 7 as shown in FIG. 3 in order to avoid such a problem. The thermal head shown here is
A glaze layer 2, a heating resistor layer 3, a lead conductor layer 4 and a protective film layer 5 are formed on a ceramic substrate 1, and after breaking into individual chips 6, the ends 7 are polished and the cutouts 8 are formed. Formed and obtuse.

(C) Problems to be Solved by the Invention In the above-mentioned conventional thermal head, since the notch 8 at the end 7 is formed by polishing, the contact surface between the horizontal plane of the end 7 of the head chip 6 and the polished slope is used. A was still sharp, and the paper and the transfer ribbon were damaged at this portion, and the problem that the print quality deteriorated remained.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a thermal head which focuses on the above-described problems and has a small number of acute-angled portions at an end portion and can further improve print quality.

(D) Means and action for solving the problems The method of manufacturing a thermal head according to the present invention is to form an insulating substrate large enough to take a number of individual thermal heads, and then to form each thermal head on the surface of the insulating substrate. A groove is formed by a cutting blade at the boundary between the regions, a glaze layer is formed using the groove as a positioning reference, and a film including a heating resistor layer, a lead conductor layer, a protective film layer, etc. is formed on the surface of the insulating substrate and on the groove. The method is characterized in that a portion is provided, and thereafter, a break is made from the groove and divided into individual thermal heads.

According to this manufacturing method, a notch cut surface is formed in advance at an end of the insulating substrate by the groove formed in the insulating substrate,
Since a film forming portion such as a heating resistor layer, a lead conductor layer, and a protective film is formed on a horizontal portion and an end cut surface on the insulating substrate, the thermal head (head chip) is divided into individual portions. In this case, the contact surface between the horizontal plane and the cut end surface is smoothed, so that the paper and the transfer ribbon are less likely to be damaged by the contact surface.

(E) Examples The present invention will be described in more detail with reference to the following examples.

FIG. 1 is a partial sectional view of a thermal head chip showing one embodiment of the present invention. In this embodiment, the thermal head chip 16 is provided with a cutting notch 18 in the form of forming an inclined surface 11a at an end portion 17 of a ceramic (insulating) substrate 11, and furthermore, a horizontal surface 11b of the ceramic substrate 11 and an inclined surface (end cutting surface). ) 11a
A glaze layer 12 is formed on a horizontal plane 11b at a position of a predetermined distance L from a contact line B with the heat generating resistor layer 13, the lead conductor layers 14, 14 and the protection layer on the ceramic substrate 11 and the glaze layer 12. The film layer 15 is formed by lamination. Of course, the heating resistor layer 13, the lead conductor layer 14, and the protective film layer 15 are also formed on the slope 11a of the ceramic substrate 11. In the thermal head chip 16, portions where the lead conductor layers 14 and 14 are not formed become print dot portions 19, and in a serial type thermal head, a plurality of the print dot portions 19 are arranged side by side in the front and back directions of the drawing.

In the thermal head chip 16, the cutting notch 18 is not formed by polishing, but a slope 11 a is formed in advance by cutting the end portion 17 of the ceramic substrate 11, and is formed on the horizontal surface 11 b and the slope 11 a of the ceramic substrate 11. In addition, since the heating resistor layer 13, the lead conductor layer 14, and the protective film layer 15 are formed, the contact line A between the inclined surface and the horizontal surface after film formation becomes very smooth. Thus, scratches on the paper and the transfer ribbon are almost eliminated.

Next, a method of manufacturing the thermal head chip of this embodiment will be described.

First, as shown in FIG. 2 (A), a V-shaped groove 20 is formed by a cutting blade at the boundary of the surface of the ceramic substrate 11 before being divided into individual chips, which is divided into individual chips. The groove may be a U-shaped groove or the like.

Next, the glaze layer 12 is formed at a predetermined distance L from the contact line B between the inclined surface 11a of the V-shaped groove 20 and the horizontal surface 11b of the ceramic substrate 11 in parallel with the V-shaped groove 20.

Thereafter, in a state where the ceramic substrate 11 is not divided into individual chips, as shown in FIG.
On the upper surface of 11, a heating resistor layer 13, a lead conductor layer 14, and a protective film layer 15 are formed. Then, after film formation, as shown in FIG. 2C, a break is made at the bottom apex of the V-shaped groove 20 to obtain an individual thermal head chip 16.

In this manufacturing method, a V-shaped groove is formed in a ceramic substrate by a cutting blade, and a heating resistor layer, a lead conductor layer, and a protective film layer are formed thereon. A notched slope can be formed at the end without polishing, and the contact line A in FIG. 1 becomes smooth, so that the paper and the transfer ribbon are not damaged during printing.

Further, in this manufacturing method, since the V-shaped groove is formed using the cutting blade, the angle of the slope of the end notch can be made large and constant by using the cutting blade having a sharp tip. it can.

Furthermore, since the V-shaped groove is formed by using the cutting blade, the contact line between the horizontal portion and the slope portion of the ceramic substrate becomes clear,
Since the glaze layer can be positioned based on this tangent line, it is convenient to keep the distance from the end to the glaze layer as small as possible and to keep it constant with high accuracy.

According to the present invention, a groove is formed on the surface of the insulating substrate after the formation of the insulating substrate, a glaze layer is formed using the groove as a positioning reference, and a heating resistor layer is formed on the surface and the groove of the insulating substrate. , A lead conductor layer, a film forming section composed of a protective film layer and the like are provided,
After that, the groove breaks, so the contact surface between the horizontal surface of the insulating substrate surface and the inclined surface of the groove is smooth, and it is less likely to damage the paper surface and the transfer ribbon at the corners of the contact surface during printing, and printing Quality is improved.

In addition, since a notch at the end is formed by breaking with a groove formed by a cutting blade at a boundary portion between each head region on the surface of the insulating substrate before being divided into individual thermal heads, a polishing process is performed. Even without it, burrs do not occur on the slope of the end notch, and not only can a smooth notch be formed, but also by using a sharp cutting blade, the angle of the slope of the end notch is large and constant. Can be

Furthermore, since a cutting blade is used, the contact surface between the horizontal surface of the insulating substrate and the inclined surface of the groove becomes clear, and this contact surface can be used as a positioning reference when forming the glaze layer, from the end of the insulating substrate to the glaze layer. Can be kept as short as possible and accurately.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a main part of a thermal head chip showing an embodiment of the present invention, and FIGS. 2 (A), 2 (B) and 2 (C). Is a view for explaining a method of manufacturing the thermal head chip, and FIG. 3 is a sectional view of a main part of the conventional thermal head chip. 11: ceramic substrate, 12: glaze layer, 13: heating resistor layer, 14: lead conductor layer, 15: protective film layer, 16: thermal head chip, 17: end portion, 18: cutting notch.

Claims (1)

(57) [Claims] After forming an insulating substrate large enough to take a number of individual thermal heads, a groove is formed at a boundary portion between the thermal head regions on the surface of the insulating substrate by a cutting blade, and the groove is positioned. Form a glaze layer as a reference,
A thermal head is characterized in that a film forming portion including a heating resistor layer, a lead conductor layer, a protective film layer, and the like is provided on the surface of the insulating substrate and on the groove, and thereafter, the film is broken from the groove and divided into individual thermal heads. Production method.