JP2554818B2 - Manufacturing method of thermal print head - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a line type thermal print head.

[0002]

2. Description of the Related Art As shown in FIG. 1, a conventionally known line-type thermal print head is provided with a linear heating element 2 on the surface of a substrate 1 made of ceramic or the like, and is arranged in parallel with the heating element 2. Both ends of the provided common pattern 4 are provided with end pattern portions 4a, 4a for external connection. Further, it is provided with a lead pattern 5 for connecting the heating element 2 and a driving circuit 3 composed of an integrated circuit, a logic pattern 6 arranged around the driving circuit 3, etc., and heats a predetermined dot portion of the heating element 2 with heat. For this purpose, a current is caused to flow from the lead pattern 5 at a predetermined location to the common pattern 4 portion adjacent to the lead pattern 5 via the heating element 2. Therefore, the end pattern portions 4a, 4 integrally formed at both ends of the common pattern 4 are provided.
a is formed and a predetermined power supply voltage is applied to the end pattern portion 4a.

Then, using the same type of drive circuit 3,
When manufacturing thermal print heads having the same dot density, a plurality of A areas are arranged side by side on the basis of the A area having one pattern forming area of the drive circuit 3 as a unit. Each pattern is formed on the surface, and end regions A at the left and right ends of the plurality of A regions are formed.
In L and AR, a wide area for forming the end pattern portion 4a is formed on the side portion of the pattern forming area per one drive circuit. As a result, the common pattern 4 and the end pattern portions 4a, 4a continuously provided at both ends of the common pattern 4 are formed on the surface of the substrate 1 for each head region in a substantially U shape in a plan view. In the conventional manufacturing method, each of the patterns is formed by etching.

[0004]

By the way, in the head having such a structure, the same drive circuit 3 is used as described above and the dot density is the same, but the printing is performed.
Heads that differ only in width may be required. In that case, in the conventional technique, a plurality of photomasks having a predetermined number of A regions and end regions AL and AR are prepared so as to correspond to the respective print widths, and a print width required from among them is prepared. Each photomask is selected and each pattern is formed by etching.

Therefore, according to the conventional manufacturing method, it is necessary to prepare many kinds of photomasks, and the designing cost and the manufacturing cost of the photomask are high. Therefore, the manufacturing cost of this type of thermal print head is high. Will also be higher. Also, 1
End areas AL and A at the left and right ends in one head area
Since R is wider than each A region due to the formation of the end pattern portion 4a, even if there is a predetermined length of the substrate that can be broken for each head region having a long print width,
There is also a problem that it is not possible to break efficiently in a head area with a narrow print width.

For example, nine A areas (width dimension ao),
The length of one head area including the end areas AL and AR (each having a width dimension a1) is (9 × ao + 2 × a1). On the other hand, 1 consisting of four A areas and left and right end areas AL and AR
To find two head areas, (8 x ao +
A length of 4 × a1) is required. In that case, when there is a substrate 1 having a length capable of forming the long print width, in order to find two short print widths from the substrate 1,
The condition that ao ≧ 2 × a1 is required. If this condition is not satisfied, a slightly longer board is required for a short print width. Therefore, it was necessary to prepare various board lengths depending on the print width.

The present invention solves the above problems and enables the production of various types of thermal print heads having different print widths by only preparing one type of photomask, and also makes it possible to produce a predetermined length. It is an object of the present invention to provide a head of this type at a low cost by enabling a head having a desired print width to be efficiently indexed from the substrate.

[0008]

In order to achieve the above object,
The present invention relates to a method of manufacturing a thermal print head having a heating element, a driving circuit, and various patterns on a surface of a substrate, wherein one pattern forming region for each driving circuit is defined as one unit, and the plurality of units are laterally arranged. To form a lead pattern and a logic pattern by etching using a photomask, and then, a common pattern for forming one head region in the pattern forming regions of the plurality of units is formed in the common pattern. A method in which an end pattern portion is formed by screen printing so as to overlap the one unit pattern forming area, and then the substrate is broken for each one head area in the one unit pattern forming area where the end pattern portion is located. Is adopted.

[0009]

Embodiments of the present invention will be described below with reference to FIGS. 2 (a), (b),
11C shows eleven (11 units) side-by-side side-by-side arrangements in which one pattern formation region of each drive circuit 3 as shown in FIG. 1 is set as one unit. On the substrate 1, nine A regions arranged in the lateral direction and end regions AL and AR located at the left and right ends thereof are secured. Then, the linear heating element 2 is provided so as to extend over all the regions, and the lead pattern 5 and the logic pattern 6 are further formed by etching using a photomask. When the thick film type head is manufactured, the heating element 2 is printed after forming the pattern. in this case,
The heating element 2 may be provided after forming each pattern.

After forming the respective patterns, as will be described later, the common pattern and the end pattern portions at both ends thereof are formed by screen printing in a U-shape in plan view so as to obtain a head having a required printing width. Then, after breaking the substrate 1 at a predetermined position so that each head area becomes,
The drive circuit 3 is provided at the location indicated by the chain double-dashed line in FIG. 1 and FIG.

For example, a case of manufacturing a thermal print head in which the required number of pattern formation areas is 3 will be described with reference to FIG. In this case, first, three pattern forming regions (including the end region AL) are secured from the left end of the substrate 1, and the left half portion of the substrate 1 and the left half position from the center of the fourth pattern forming region adjacent thereto. The common pattern 11 parallel to the heating element 2 and connected to the left and right end portions of the common pattern 11 to form end pattern portions 11a and 11a at the left end portion of the end area AL. And the fourth pattern formation region are formed by screen printing so as to be located respectively on the left half of the center of the fourth pattern formation region.

Similarly, three areas are secured from the fifth pattern forming area, and the right half of the left and right center of the fourth pattern forming area and the center to the left of the eighth pattern forming area are left. The common pattern 11 is parallel to the heating element 2 and is connected to the left and right end portions of the common pattern 11 to extend up to half of the positions, and the end pattern portions 11a and 11a are connected to the fourth pattern. It is formed by screen printing so as to be located at the right half of the center of the formation area and the left half of the center of the eighth pattern formation area.

Further, for the area on the right side of this,
The common pattern 11 and the end pattern portions 11a and 11a are formed in substantially the same manner as described above. Actually, the three common patterns and the end pattern portions at both ends thereof may be simultaneously formed by screen printing. As described above, the lead pattern 5 and the logic pattern 6 are already formed in the fourth and eighth pattern forming regions, but the left and right center portions in the fourth region from the left end of the substrate 1 And the left and right center portions in the eighth area are break points (see the alternate long and short dash line in FIG. 2A), so that the drive circuit 3 is not mounted in these areas and there is no relation to lead connection. Therefore, the common pattern 11 and the end pattern portion 11 are added to the patterns 5 and 6 in this region.
The lead connection is not affected even if a and 11a are printed by overlapping from above.

After the screen printing, if the substrate 1 is broken from the left and right center positions of the fourth and eighth pattern forming regions as shown by the alternate long and short dash line, the thermal printing is performed with three pattern forming regions. You will be able to manufacture 3 heads. Next, a case will be described where a head having five required pattern formation areas is formed. In this case, as shown in FIG.
5 pattern forming regions (including the end region AL) are secured from the left end of the substrate, and the sixth half of the pattern forming region adjacent to the right of the substrate extends across the left half of the left and right center from the left end of the substrate 1. The common pattern 12 is parallel to the heating element 2 and is connected to the left and right ends of the common pattern 12 to form the end pattern portions 12a and 12a at the left end portion in the end area AL and the sixth pattern. It is formed by screen printing so that it is located at the left half of the center of the formation area.

Further, the region on the right side of this is similarly formed. That is, the common pattern 12 is formed in parallel with the heating element 2 and across the right half portion of the sixth pattern formation region from the right and left center of the substrate 1 and the right end portion of the substrate 1. The end pattern portions 12a, 12a are formed by screen printing so as to be connected to the left and right end portions so as to be respectively located at the right half portion from the center in the sixth pattern forming area and the right end portion in the end area AR. To do.

After that, the substrate 1 is broken at the right and left center of the sixth pattern formation region as shown by the alternate long and short dash line. By this, the number of areas (the number of pattern formation areas)
It is possible to manufacture two heads with five. When the number of pattern formation regions required is 11, FIG.
As shown in FIG. 2C, nine A regions and left and right end regions AL and AR are provided on the substrate 1 having substantially the same length as shown in FIGS. 2A and 2B, as described above. The heating element 2 is secured and the lead pattern 5 and the logic pattern 6 are provided.
Prepared by etching using a photomask in the same manner as described above, the common pattern 13 extending to both left and right ends of the substrate 1 is parallel to the heating element 2, and the end pattern portions 13a and 13a are formed as described above. Left and right edge areas AL, A
It is formed by screen printing so that it is located at each end of R. In this case, one head can be manufactured as shown in FIG. 2C without breaking the original substrate 1.

Even if a pattern is formed using the same photomask as described above, various heads having different print widths can be manufactured. As shown in the drawing, when the pattern 7 for connecting the input / output terminals of the adjacent drive circuits 3 is formed across each area, when the common patterns 11, 12 and the like are formed thereafter, The pattern 7 may short-circuit due to the common pattern.

In order to avoid this, for example, if the pattern 7 is not formed continuously between the adjacent regions and is cut in the middle, the pattern 7 is not short-circuited. Then, the patterns 7 that need to be connected later may be connected to each other by wire bonding. Alternatively, an external circuit to be connected later, for example, a conductor of a flexible wire (FPC) may be used for connection.

Further, in the drawing, the heads arranged in the lateral direction are shown as one stage, but in actual production, this may be produced by patterning multiple stages, for example, three stages simultaneously.

[0020]

As described in detail above, according to the present invention,
Various types of thermal print heads with different print widths can be arbitrarily manufactured from those having a pattern formed by etching using the same photomask. It is no longer necessary to prepare, and the design cost and production cost of this kind of head are reduced accordingly.

Further, since a plurality of heads are indexed from a long substrate, when the common pattern and the end pattern portions at both ends thereof are screen-printed, at least the end pattern portions in the adjacent head regions are set at 1 at least at the left and right intermediate positions of the substrate. It is arranged so as to be overlapped and adjacent to the unit pattern formation region. In other words, when dividing into a plurality of heads, it is not necessary to separately form the above-mentioned wide end regions at the left and right end portions of one head region as in the conventional case, and a pattern forming region having the same (common) width dimension is formed. Since the edge pattern part can be formed in that area by using the, the length of the substrate before indexing can be made common, and it is necessary to prepare various substrate lengths due to the difference in the printing width as in the conventional case. Without
There is also an effect that a head having a desired print width can be efficiently indexed from a substrate having a predetermined length.

Further, after the pattern is etched, it may be stored in stock, and after that, various heads can be manufactured in accordance with an order, and therefore, there is an effect that the delivery time can be greatly shortened.

[Brief description of drawings]

FIG. 1 is a plan view for explaining an embodiment method of the present invention.

FIG. 2A is a plan view showing a pattern such as a common pattern by screen printing when divided into three heads, and FIG. 2B shows a common pattern by screen printing when divided into two heads. A plan view showing the pattern,
(C) is a plan view showing a pattern such as a common pattern by screen printing when one head is formed.

FIG. 3 is an enlarged plan view of an essential part of FIG.

[Explanation of symbols]

 1 substrate 2 heating element 3 driving circuit 4 common pattern 4a, 4a end pattern part 5 lead pattern 6 logic pattern 7 pattern 11, 12, 13 common pattern 11a, 12a, 13a end pattern part A area AL, AR end area

Claims (1)

(57) [Claims] 1. A method of manufacturing a thermal print head having a heating element, a driving circuit, and various patterns on a surface of a substrate, wherein one pattern forming region for each driving circuit is defined as one unit, and a plurality of units are laterally arranged. A lead pattern and a logic pattern are formed by etching using a photomask so as to be aligned in the direction, and then a common pattern for forming one head region in the pattern forming regions of the plurality of units is appropriately used. Is formed by screen printing so that the end pattern portion of the unit overlaps the pattern formation region of one unit, and then the substrate is broken for each head region in the pattern formation region of one unit where the end pattern unit is located. A method of manufacturing a thermal print head, comprising: