JPH0253231B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a serial thermal head, and more particularly to a method for manufacturing a serial thermal head for extracting a plurality of thermal heads with excellent wear resistance from a single wafer.

First, a conventional method for manufacturing a serial thermal head will be explained based on FIGS. 1 to 3.

As is clear from Fig. 1, one wafer 1
Thermal heads are disposed above so as to face each other, and a heating element 5 is formed on the upper surface of the glaze layer 6. When forming the glaze layer 6, an opening 12 shown in FIG. Glass paint for a glaze layer is printed on the wafer 1 using the screen mask 11, and then heat treatment is performed to form a glaze layer 6 corresponding to the openings 12. A heating element 5 and an electrode 4 are formed on this, and the wafer is covered with a mask 13 having an opening 14 shown in FIG. 3, and a protective film is formed in the formation area 3. In this case, this glaze layer is formed by integrating each glaze layer 6 in two thermal head chips as shown in FIG.
Finally, two thermal head chips are completed by cutting along line A--A in FIG. in this way,
Since a large number of thermal head chips 2 are formed on one wafer 1 at the same time, a large number of thermal head chips 2 can be obtained simultaneously by cutting along the A--A line.

Since the conventional thermal head chips 2 are manufactured by the manufacturing method described above, when this wafer is cut along the line A-A, one end of the glaze layer 6 of each thermal head chip will be cut as shown in FIG. Its end 7 has a right-angled corner 7a.
and uneven portions 8 due to chipping of the glaze layer 6
is formed.

FIG. 5 shows an example in which the thermal head thus manufactured is incorporated into a serial thermal printer, and FIGS. 6a and 6b are a front view and a side view of the thermal head at that time.

This kind of serial thermal printer has a board 16
A thermal head 15, on which a glaze layer 6, a heating element 5, etc. are formed, is placed in pressure contact with a platen 18 through a thermal paper 17. Power is supplied to the heating element 5 to generate heat, and the thermal head 15 is placed on the thermal paper 17. While sliding the thermal paper 17, desired information is recorded on the thermal paper 17.

Therefore, since the glaze layer 6 of the thermal head made by the conventional manufacturing method has uneven parts 8 formed at its edges, when the thermal head slides on the thermal paper, the paper will not touch the surface of the thermal head. This has the disadvantage that the thermal head itself may be damaged or paper waste may be generated at the corner 7a, significantly shortening the life of the thermal head itself.

The object of the present invention is to provide a method for manufacturing a thermal head that does not have the above-mentioned drawbacks.

Hereinafter, a method for manufacturing a serial thermal head according to the present invention will be explained with reference to the drawings.

7 to 10 show one embodiment of a method for manufacturing a serial thermal head according to the present invention.

As shown in FIG. 7, a plurality of thermal head chips 2 are arrayed on one wafer 1 so as to face each other. Reference numeral 6 indicates a glaze layer, 3 indicates a protective film forming area formed in a band-shaped area on the surface of the thermal head chip, 4 indicates a lead electrode not covered with a protective film, and 5 indicates a heating element. It is formed.

First, glass paint is printed on the upper surface of the wafer 1 using a screen mask 19 having a plurality of elongated openings 20 and 21 shown in FIG. 8, and then baked to obtain a plurality of glaze layers 6.

At this time, between the opposing openings 20 and 21 of the screen mask 19 in FIG. 8, there is a masked part 22 where glass paint cannot be printed, and this part matches the divided part C of the wafer in FIG. Align as shown.

Next, after forming the heating element 5 and the electrode 4, a mask 13 having an opening 14 as shown in FIG.
is set on the wafer, and a protective film having a thickness of 5 to 8 microns made of tantalum pentoxide or silicon dioxide is formed in the protective film forming region 3 of FIG. Thereafter, the wafer is divided along lines B and C in FIG. 7 to obtain serial thermal heads.

The serial thermal head obtained by the above process is divided by printing and firing the glaze layer 6 in an independent pattern on each thermal head chip, and dividing the wafer at a point C slightly away from the glaze layer. The glaze layer of the thermal head obtained by this method does not have sharp portions at least in its ridgeline portions.

9, 10a and 10b show the completed state of the serial thermal head according to the manufacturing method of the present invention, in which the substrate 1
A convex glaze layer 6 having an elongated shape with an arcuate cross section in the transverse direction is formed on the glaze layer 6, and a plurality of heating elements 5 are formed along the longitudinal ridge line 9 of the upper surface of this glaze. A plurality of lead electrodes 4 for connection to the outside are formed at one end of the substrate 16,
Although not shown in the drawings, each heating element 5 and the lead electrode 4 are connected to each other. As shown in the perspective view of FIG. 9 and the cross-sectional view of FIG. 10b, the longitudinal end portion 7 of the glaze layer 6 has a smooth surface due to firing and melting of the glaze layer, and also has a smooth surface along the ridge line of the glaze layer. A surface having a gentle slope from 9 to the surface of the substrate is formed, and therefore, the thermal paper 17 shown in FIG. This is a configuration in which the two sides touch each other.

The greatest feature of the thermal head obtained by the present invention is that the surface of the end portion 7 of the glaze layer forms a curved surface.
When the thermal head 15 is brought into contact with the thermal paper 17 and slid to perform a printing operation, the thermal paper 17 is scraped because the glaze layer does not have sharp parts on the sliding surface with the thermal paper unlike in the past. You won't have to worry about it.
Stable sliding can be performed.

In the above embodiment, the wafer is divided at a point C that is slightly away from the glaze layer, but even if the wafer is divided at a plane that has a gentle slope from the ridge 9 of the glaze layer toward the substrate, the same result will occur. Effects similar to those of the embodiment can be obtained.

FIGS. 11a and 11b and FIG. 12 show yet another embodiment. Reference numeral 23 denotes a V-shaped groove with a moderately inclined surface provided on the main surface of the wafer 1, and the glaze layer 6 straddles this groove 23 and is connected between the two thermal head chips 2 facing each other. It is formed in a vertical pattern and is formed through the steps described below.

First, after forming the grooves 23 in the parts corresponding to the divided parts B and C shown in FIG. 7, the screen mask 19 shown in FIG.
2 to the grooves 23 corresponding to the divided portions C, glass paint is printed and fired to obtain a plurality of glaze layers 6.

The glaze layer 6 printed and fired across such a groove 23 has a groove in the groove 23 and a groove where the glaze is melted by firing, as shown in a cross-sectional view in FIG. 11b. The flow results in depressions k in the grooves 23 on the surface of the glaze layer.

Next, the heating element 5, lead electrode 4, and protective film are formed in the same manner as in the embodiment shown in FIG. Thereafter, the wafer is divided along the grooves 23 to obtain serial thermal heads.

Therefore, the serial thermal head obtained by dividing the wafer 1 shown in FIG. 11a above at the groove 23 has the following cross-sectional views as shown in FIG.
The dividing plane X at the end of the substrate is away from the contact portion with the thermal paper 17, and becomes a smooth curved surface at least near the contact portion with the thermal paper on the surface of the glaze layer.

In the serial thermal head according to the present invention formed as described above, the longitudinal end surface of the elongated glaze layer has a smooth curved surface.
Even in serial thermal printers, where the thermal head prints while sliding in various directions against the thermal paper, the surface of the thermal paper is not scraped off, and the amount of paper waste generated during long printing operations is shown in Figure 13. As shown, this is much less than in the case of a conventional thermal head with a glazed layer having sharp edges. Accordingly, Figures 14 and 15
As shown in FIG. 16, the amount of scratches and abrasion on the surface of the thermal head, as well as the rate of occurrence of abnormalities due to paper dust in the printer, can be significantly improved compared to conventional printers.

[Brief explanation of the drawing]

Figure 1 is a partial plan view showing a conventional example of removing a large number of thermal heads from a wafer;
The figure is a plan view showing the screen mask used for glaze printing in Fig. 1, Fig. 3 is a partial plan view showing the protective film forming mask in Fig. 1, and Fig. 4 is a plan view showing the screen mask used for glaze printing in Fig. 1. FIG. 5 is a partially cutaway perspective view of the general configuration of a serial thermal printer, FIG. 6a is a front view of the thermal head in FIG. 5, and FIG. Figure b is a side view in Figure 5;
FIG. 7 is a plan view showing the arrangement of thermal head chips on a wafer according to the present invention, and FIG.
9 is a perspective view of a thermal head obtained by the present invention, FIG. 10a is a front view of the thermal head of FIG. 9, and FIG. 10b is a plan view showing a screen mask used for printing a glaze layer. teeth,
FIG. 9 is a side view showing the relationship between the thermal head and thermal paper; FIGS. Figure 12 shows the 11th
Figures 13 and 14 are side views showing the relationship between the thermal head chip and thermal paper obtained by the method shown in the figure.
15 and 16 show comparative examples of the performance of a conventional thermal head and a thermal head obtained according to the present invention. FIG. 4 is a diagram showing the amount of head wear, the amount of head wear, and the abnormality occurrence rate of the printer. 1... Wafer, 2... Thermal head chip, 3... Protective film formation area, 4... Lead electrode,
5... Heating element, 6... Glaze layer, 7... Longitudinal end, 8... Uneven portion, 9... Ridge line, 11...
Screen mask, 12... Opening, 13... Mask, 14... Opening, 15... Thermal head, 16... Substrate, 17... Thermal paper, 18... Platen, 19... Screen mask, 20, 21
...Aperture, 22...Part that cannot be printed, 23...
...V-shaped groove.

Claims (1)

[Scope of Claims] 1. A method for manufacturing a serial thermal head having at least a glaze layer, a heating element, and an electrode for supplying power to the heating element, wherein the individual serial thermal heads are manufactured on one wafer. A plurality of elongated glaze layers constituting the glaze layer are printed facing each other with a gap between each other, and both ends of the glaze layer in the direction of the ridge line (the highest part of the convex portion) are fired and melted to extend from the ridge line toward the surface of the wafer. Once a smooth inclined surface is formed, a plurality of heating elements are formed along the surface of the ridge of the glaze layer, an electrode for supplying power to the heating element is formed, and the wafer is moved along the longitudinal direction of the glaze layer. A plurality of thermal heads can be obtained from a single wafer by dividing the glaze layer at the inclined surface of the glaze layer, which serves as a directional ridgeline, or by dividing it at the outside of the inclined surface and at the boundary line between adjacent thermal heads. Characteristic serial thermal head manufacturing method. 2. A V-shaped groove that divides the serial thermal head is formed in advance on the wafer, and a plurality of the glaze layers are printed facing each other with a gap between the grooves. A method for manufacturing a serial thermal head according to scope 1.