JPH0447952A - thermal head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal print head used in a thermal printer.

<Prior art> As shown in the shaded area in Figure 6, in conventional thermal print heads, the method of aligning the partially glazed glass and the thin film pattern during photolithography is often in a cross shape, which is the position of the thin film pattern relative to the partially glazed glass shape. It was difficult to match. Furthermore, when manufacturing various thermal print heads by changing the main scanning distance of the heating resistors (distance from the edge of the board to the center of the heating resistor row), it was necessary to prepare various types of photomasks. .

<Problems to be Solved by the Invention> In the conventional thermal print head, as shown in the photolithography process in Figure 3, a heating resistor and an electrode are formed on a heat-resistant insulating substrate by a photolithographic etching method using a positive resist. When manufacturing a thermal head, when positioning a heating resistor photomask overlapping a pattern at an arbitrary position on a partial glaze glass, the photomask is a positive resist type, so the partial glaze glass used as a reference must be used. The shape was difficult to see through a photomask, and sufficient pattern position accuracy could not be obtained.

For this reason, when manufacturing an edge-type thermal head, due to the length (positional deviation) of the distance to the center of the heating resistor formed on the partially glazed glass, poor transferability especially to rough paper and white spots during high-speed printing may occur. This was causing printing.
Also, when manufacturing various types of thermal print heads by changing the main scanning distance of the heating resistors (distance in meters from the end surface of the substrate to the center of the heating resistor row), it is necessary to prepare photomasks for each type. This was the cause of high design and manufacturing costs for thermal print heads. The present invention solves these problems and improves the design and design of thermal print heads.
The aim is to reduce production costs and provide high-quality thermal print heads.

<Means for solving the problem> (1) Partially glazed glass is placed on a ceramic or heat-resistant insulating substrate, and a heating resistor layer, an electrode layer, and a protective film layer are laminated on the surface of this substrate, In a thermal print head provided with a large number of heating resistor elements, each pattern of which is formed as a thin film by a photoetching method, the heating resistor is provided on partially glazed glass, and the partially glazed glass and thin film are formed. The photolithographic alignment of the pattern is characterized by alignment marks that can be aligned simultaneously in the longitudinal and lateral directions of the partially glazed glass.

(2) The photolithographic alignment mark between the partially glazed glass and the thin film pattern is characterized by a comb-teeth shape.

(3) The photolithographic alignment mark for the partial glaze glass and the thin film pattern is characterized in that it has a window for lateral alignment of the partial glaze glass.

<Example> Embodiments of the present invention will be explained below.

FIG. 1 shows a plan view showing the entire thermal print head according to the present invention. FIG. 2 is a side sectional view showing the vicinity of the heating resistor portion according to the present invention. FIG. 4 is a detailed view of the heating resistor portion and alignment pattern of the thermal head in the present invention. In the figure, 1 is a heat-resistant insulating substrate, 2
3 is a heat-resistant partially glazed glass, 3 is a heating resistor layer, 4 is an electrode layer, 5 is a protective layer with abrasion resistance and oxidation resistance that protects 3 and 4, and 6 is an alignment mark for the heating resistor photomask pattern. It is. In the figure, a heating resistor layer 3 and an electrode layer 4 are formed on a heat-resistant insulating substrate 1 using a vacuum thin film apparatus such as sputtering. Next, as shown in the photolithography process in Figure 3, a photoresist is coated on the entire surface of this laminated film using a general spin coater, roll coater, etc., and after blebake (pre-drying), it is exposed to light using a photomask for the heating resistor. After forming a pattern by developing and etching, the resist is peeled off to form a thin film pattern. Since the photoresist is not exposed to light in the shaded area in FIG. 3, when the resist is removed after etching, the heating resistor layer is formed as a heating resistor pattern as shown in the shaded area in FIG. In this exposure process, the method of aligning the partial glaze glass and the heat generating resistor photomask pattern is as shown in part a of Figure 4. Using the cutout pattern), align the center of the alignment mark (the entire pattern) so that it is approximately at the center of the partially glazed glass, then use the external shape line of the partially glazed glass as a reference, and align the longitudinal comb teeth and the horizontal direction of the alignment mark. The comb teeth simultaneously perform fine alignment in the longitudinal and lateral directions with respect to the partially glazed glass to form a heating resistor pattern.

Also, when manufacturing a thermal print head by varying the main scanning distance of the heating resistor (distance from the end surface of the substrate to the center of the heating resistor row) using one type of heating resistor photomask and electrode photomask. , using a photomask for a heating resistor equipped with alignment marks in the form of longitudinal comb teeth and lateral comb teeth, the center of the alignment mark is positioned at the center of the partially glazed glass, as shown in part a of Figure 4. Positioning is performed at the same time using the longitudinal comb teeth and the comb teeth of the horizontal comb-shaped alignment mark. Next, using a photomask for electrodes, as shown in FIG.
As shown in Figure 5, the amount of overlap between the lateral comb teeth of the heat generating resistor photomask and the alignment mark of the electrode photomask is varied, and the main scanning side distance of the heat generating resistor is adjusted for each substrate without changing the photomask. Different types of thermal print heads can be manufactured. Since the photoresist is exposed to light in the shaded area in FIG. 6, when the resist is removed after etching, an electrode layer is formed as an electrode pattern as shown in the shaded area in FIG.

Thereafter, a protective layer having wear-resistant and oxidation-resistant functions for protecting the heating resistor layer and the electrode layer is formed on this thin film pattern using a vacuum thin film apparatus such as sputtering.

<Effects of the Invention> As explained above, the following points are improved by using the thermal print head according to the present invention.

(1) When manufacturing a thermal print head, in the alignment of the partially glazed glass on the heat-resistant insulating substrate and the photomask pattern for thin film pattern formation during the photolithography etching/exposure process, the longitudinal direction with respect to the partially glazed glass is determined. By using a photomask equipped with comb teeth and lateral comb teeth, a thermal print head with good positional accuracy of the heating resistor can be manufactured.

(2) Also, when producing various types of thermal prints by varying the distance on the main scanning side of the heating resistor, there is no need to prepare various types of photomasks, reducing the design and manufacturing costs of the thermal print head. be able to.

As described above, the present invention contributes to improving quality and reducing head costs.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the entire thermal print head according to the configuration of the present invention. FIG. 2 is a cross-sectional view of the area around the heating resistor of the thermal print head. Figure 3 is a diagram of the photolithography process for the heat-generating tank specimen. FIG. 4 is a detailed view of the heating resistor part and alignment marks. FIG. 5 is a superimposed diagram of the heating resistor and electrode positioning marks. Figure 6 is a photolithography process diagram of the electrode. FIG. 7 is a detailed diagram of the electrode pattern. FIG. 8 is a diagram showing alignment marks of a thermal print head with a conventional configuration. 1 ・ 2 ・ 3 ・ 4 ・ 5 ・ 6 ・ 7 ・ 8 ・ 9 ・ Heat-resistant insulating substrate, heat-resistant partial glaze glass, heat-generating resistor layer, electrode layer, protective film layer, photomask, resist, heat-generating Alignment marks for resistor/alignment marks for electrodes Above Figure 1 Figure 5 Figure 3 Figure 6 Figure 4 Figure 7 Figure 8

Claims (3)

[Claims] (1) Partially glazed glass is placed on a ceramic or heat-resistant insulating substrate, and a heating resistor layer, an electrode layer, and a protective film layer are laminated on the surface of this substrate, and each pattern is formed into a thin film by photo-etching. In the thermal head provided with a large number of heating resistor elements, the heating resistor is provided on partially glazed glass, and photolithographic alignment of the partially glazed glass and the thin film pattern is performed on the partially glazed glass. A thermal head characterized by alignment marks that can be aligned in both the longitudinal and lateral directions. (2) The thermal head according to claim 1, wherein the photolithographic alignment mark between the partial glaze glass and the thin film pattern is comb-shaped. (3) The thermal head according to claim 1, wherein the photolithographic alignment mark for the partial glaze glass and the thin film pattern has a window for lateral alignment of the partial glaze glass.