JPH036916B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for manufacturing a line-type thermal head, and more particularly to a method for manufacturing a line-type thermal head by connecting short thermal heads in the longitudinal direction to make a long thermal head.

(Prior art and its problems) As a method of manufacturing a long line type thermal head, when forming it on a long substrate of a desired length from the beginning, even one of the many heat generating parts is defective. If this happens, the entire thermal head will be a defective product, lowering manufacturing yields and increasing costs. Conventionally, a large number of heat-generating parts with the same pattern are formed on a long substrate, and then the desired parts are cut using a diamond blade or a laser scriber to create a short thermal head, as shown in Figure 1. A method is used in which good quality products are selected from these short heads and joined together in the longitudinal direction to form a long thermal head. In the figure, 1 is a resistor, 2
is the electrode, 3 is the substrate, 4 is the cutting groove, and the arrow is the cutting groove 4.
represents the direction of travel.

Since a glazed ceramic substrate is usually used as the substrate 3, when cutting with a diamond blade, for example, if the resistor pattern is cut too close, chipping may occur and the shape of the resistor pattern may be damaged. be. Therefore, as shown in FIG. 1, it is necessary to cut the ends 5, 5' leaving a large margin. Also, when cutting using a laser scriber, if you cut too close to the resistor pattern, the reliability of the resistor and electrodes may be impaired due to the influence of heat, so in this case too, It must be cut leaving a large margin.

Therefore, when the cut short thermal heads are joined together at their respective cut ends 5 and 6 to form a long line-type thermal head, the resistor pattern pitch is formed at the connection point, as shown in Figure 2.
P ₁ becomes larger than the resistor pattern pitch P ₂ in other parts, and the margin area also becomes large, and when printing, printing is not done in this area, resulting in white streaks and poor print quality. There's a problem.

(Objective) The object of the present invention is to manufacture a thermal head with excellent printing quality in a method of manufacturing a line-type thermal head by joining together thermal heads cut into short lengths.

(Structure) In the present invention, when forming a heat generating part on a long substrate, the resistor pattern of the heat generating part has a width in the longitudinal direction of the head of the resistor pattern adjacent to the cut point, which is equal to the head of the resistor pattern in other parts. The resistor pattern is formed so that it is larger than the width in the longitudinal direction, and the wide resistor pattern is cut at the same time.Only the good quality short heads made in this way are connected to form a line. It manufactures mold heads.

Examples of the present invention will be described below.

FIG. 3 shows resistor patterns and electrode patterns formed on a long substrate near the cut portion. 11 and 11' are resistor patterns adjacent to the cutting points 4 and 4', and the width _W1 of these resistor patterns in the longitudinal direction of the head is the width W1 of the resistor pattern 1 in the other portions in the longitudinal direction of the head. It is formed larger than ₂ .

Next, the thermal head on this long substrate is cut with a diamond blade at predetermined cutting positions 4 and 4', but the cutting is done so that the wide resistor patterns 11 and 11' are also cut at the same time as shown in the same figure. Do it in a suitable position.

In the short thermal head obtained by cutting in this way, the resistors 11 and 11' at both ends are connected to the cut end surfaces 5 and 11'.
5' and there is no margin at the end.
Therefore, when such short thermal heads of good quality are connected, the connection part is such that the resistor patterns 11 and 12 face each other at the ends 5 and 6 without intervening the blank space of the board, as shown in Fig. 4. become. As shown in the figure, it is not difficult to make the resistor pattern pitch at the connection part equal to the resistor pattern pitch _P2 at other parts, and therefore the thermal head will not produce white streaks when printed. .

According to this embodiment, the printing density is 4 dots/mm.
Or not only 8 dots/mm but also 12 dots/mm
Even with a thermal head for high-density printing such as 16 dots/mm or even 16 dots/mm, high quality printing without white streaks can be obtained.

Here, to give an example of the dimensions, the resistor pattern pitch _P2 of the part not adjacent to the cutting point is 250 mm, corresponding to a printing density of 4 dots/mm to 16 dots/mm.
~62.5 μm. Further, since the length of the margin between the resistor patterns is suitably 10 to 20 μm, the width W ₂ of the resistor pattern 1 that is not adjacent to the cutting portion is 240 to 40 μm, corresponding to the above-mentioned printing density. Further, when cutting with diamond grade, the width of the cutting structures 4, 4' is 50 to 150 μm. Therefore,
Resistor patterns 11, 11' adjacent to the cutting location
The width W ₁ is set larger than W ₂ based on the above dimensions.

In FIG. 3, resistor patterns 11 and 11'
may be connected. Also, in the same figure, there are two locations 4,
Although it is cut at 4', it may be cut at only one location.

FIG. 5 shows a connection part of a thermal head manufactured according to another embodiment, and as in the conventional example shown in _FIG . This is an example where it is wider than ₂ . However, even in this case, according to the present invention, since the resistor exists up to the ends 5 and 6 of each short thermal head, there is little margin at the connection part, and white streaks may occur when printing. There isn't.

FIG. 6 shows an embodiment in which the present invention is applied to a thermal head having a meandering resistor pattern. Even in this case, the resistor patterns formed on the long substrate are those 21, 21,
In the case of the head 22, the width in the longitudinal direction of the head is made wider than that of the other types 20, and the head is cut at a position passing through the wide resistor pattern, and there is no difference from the previous embodiment.

FIG. 7 shows still another embodiment, in which not only the width of the resistor patterns 11 and 12 adjacent to the cut point but also the width of the electrode patterns 23 and 24 connected to the resistor patterns in the longitudinal direction of the head are widened. This is an example of the formation. According to this example, compared to the case shown in FIG. 5, the current flows in the direction of the connection between the resistor patterns 11 and 12 better, and the function of preventing white streaks from occurring can be more reliably achieved. .

Note that the present invention is also applicable to manufacturing methods other than thermal heads, such as when long objects are required, such as full-scale sensors and displays, and where short objects are joined together to make a long object for manufacturing reasons. It can be applied to

(Effects) As described above, in the present invention, a thermal head made on a long substrate is cut at a position passing through a resistor pattern adjacent to the cut point to form a short thermal head, so that such a short thermal head can be connected. A thermal head manufactured in accordance with the above method has less blank space at the connection part, and therefore, it is possible to prevent the occurrence of white streaks when printing. As described above, according to the present invention, a thermal head with excellent printing quality can be manufactured while maintaining low cost.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a resistor pattern formed on a long substrate by a conventional method and cutting locations, and FIG. 2 is a plan view showing the vicinity of a connection part of a thermal head manufactured by a conventional method. FIG. 3 is a plan view showing a resistor pattern formed on a long substrate according to an embodiment of the present invention and cutting locations, and FIGS. 4 to 7 are connections of thermal heads each manufactured according to an embodiment of the present invention. It is a top view showing the vicinity of the part. 1, 20... Resistor pattern not adjacent to the cutting location, 2, 23, 24... Electrode, 4... Cutting groove,
11, 11', 12, 21, 22...Resistor pattern adjacent to the cutting location, _W1 , _W2 ...Resistor pattern width.

Claims (1)

[Claims] 1 A method of creating a line-type thermal head by cutting a thermal head made on a long board into short heads of a predetermined length and joining a plurality of the good short heads in the longitudinal direction to make a line type thermal head. For the resistor pattern to be cut, the width in the longitudinal direction of the head of the resistor pattern adjacent to the cutting point is formed wider than the width in the longitudinal direction of the head of the resistor pattern in other parts, and when cutting, A method for manufacturing a thermal head characterized by cutting a body pattern at the same time.