JPS63111065A - End face type thermal head - Google Patents

Abstract

PURPOSE:To enable a high resolution performance to be obtained with a good yield even though a thick film electrode is used, by a method wherein a lead wire part in an individual electrode layer is made a two-layered structure and at the same time, an arrangement of each lead wire layer is shifted by one half pitch with each other. CONSTITUTION:A discrete electrode layer 4 is divided into an electrode part 4 positioned near the end face of a substrate 1 and a lead wire part 42 in the center of the substrate, and this lead wire part 42 is composed of the first and the second lead wire layers 421, 422 laminated via an insulating layer 31. The first and the second lead wire layers 421, 422 are so printed that wiring patterns are shifted by one half pitch respectively with each other. In such a constitution, since high wiring density following the high resolution of the discrete electrode layer 4 is limited only in an electrode part 41 of a small area near the end face of the substrate, an area requiring a high density pattern is lessened and the yield in manufacturing time can be increased. Further, since a wiring density per layer of the first and the second lead wire layers 421, 422 is decreased in the lead wire part 42, when a driver IC chip or the like is loaded on the substrate, the wiring pattern can leave a margin in capacity and the connection therewith is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an end face type thermal head in which a heating resistor is formed in the direction of the end face of a substrate.

[Conventional technology]

Conventionally, an edge-type thermal head in which a heating resistor is formed at the edge of a substrate has been developed by the applicant in 1973! -213
There is a device that has already been filed as No. 1H. 1!41
1 is a block diagram showing an outline of this thermal head. The thermal head shown in the figure has a common electrode layer 2. Glass serving as both an electrical insulation layer and a heat resistance layer 13.
Individual electrode layer 4. The protective glass layer 5 is sequentially laminated, and each layer including the substrate 1 is renewed, and each electrode layer 2 is
, 4, a heat generating resistor 6 is formed on the exposed end face of each. Alumina or the like is used for the substrate l, and gold (Au), platinum (Pt) or the like is used for the electrode layer.

The electrode layer and the glass layer can be easily formed using thick film technology. Further, the heating resistor 6 is separated into a plurality of parts by laser cutting 7 or the like in accordance with the shape (electrode pitch) of the individual electrode layer 4. Furthermore, although not shown in the figure, a protective and wear-resistant layer is formed on the first heating resistor 6.

In the end-face type thermal head formed in this manner, one heating resistor 6 (heating portion) comes into reliable contact with the recording paper, etc., so that a thermal head with good thermal efficiency can be obtained. Furthermore, since the end portions of the substrate 1 can be more easily processed to be flat than the flat portions, the plurality of heat-generating portions can be brought into even contact with the recording paper, etc., and high printing quality can be obtained.

Furthermore, since the length of the heat generating part in the heat generating resistor 6 is determined by the thickness of the glass layer 3 formed between the electrode layers, the length of the heat generating part can be freely controlled by setting this thickness to ms. The size of the printed dots can be selected without affecting the strength of the substrate 1.

[Problem that the invention seeks to solve]

However, in such an end-face type thermal head, since the common electrode layer 2 and the individual electrode layers 4 are formed by thick film printing, the wiring density of the nine individual electrode layers 4 cannot be made very high, and the head There are limits to how high resolution can be achieved. In addition, in order to increase the wiring density of the individual electrode layer 4 as much as possible and achieve high resolution, there is a method of forming an electrode pattern by photolithography using a thick gold film with a reduced amount of glass frit. has also been put into practical use, but in order to form an electrode pattern (wiring pattern) over the entire surface of the substrate 1, the resolution is limited to about 8 to 10 wires/m, and higher resolution (H ~ - degree) high resolution results in poor manufacturing yields and is not practical.

The purpose of the present invention is to eliminate the above-mentioned drawbacks of conventional devices and to realize an end-face type thermal head with a simple configuration that can achieve good yield and high resolution even when using conventional thick film electrodes. That is.

[Means for solving problems]

The end face type thermal head of the present invention is 1 individual type 8! A plurality of electrode layers serving as a common electrode layer or a common electrode layer are sequentially stacked on one surface of the substrate so as to face each other with a glass layer serving as an electrical insulating layer and a thermal resistance layer interposed therebetween, and an exposed end surface of each electrode layer is formed. In an edge-type thermal head in which a heating resistor is formed on the substrate, the individual electrode layer is divided into an electrode portion near the end surface of the substrate and a lead wire portion in the center of the substrate, and the lead wire portion is laminated with an insulating layer interposed therebetween. In addition, the lead wire pattern devices in these two lead wire layers are shifted by 1/2 pitch from each other so that each of these lead wire patterns is guided to the electrode portion of one layer. This is what I did.

[For production]

In this way, the lead wire portion of one individual electrode layer has a two-layer structure, and the devices of each lead wire layer are arranged at 172 points from each other.
By shifting the pitch in increments, the wiring density increases as the resolution increases only in the small area of the electrode near the end face of the substrate, so that the yield during manufacturing can be improved. Further, since the wiring density per layer in the lead wire portion is reduced, when a driver IC chip or the like is mounted on the substrate, it becomes easy to connect with the driver IC chip or the like.

[Example] The end face type thermal head of the present invention will be described below with reference to the drawings.

Fig. 1 is a configuration diagram showing one embodiment of the end-face type thermal head of the present invention.In Fig. 0, which shows the manufacturing process in order, the same parts as in Fig. 4 are designated by the same reference numerals. 641 shown attached is close to the substrate end surface of the individual electrode layer 4! The horizontal part, 42, is the lead wire part at the center of the board.
421 and 422 are the lead wire portions 41fc4i1 and 111 and the second lead wire layer, and 31 is an insulating glass layer laminated between the first and second lead wire layers 421 and 422.

Now, the manufacturing process of the end face type thermal head of the present invention is as follows.

Specifically, as shown in FIG.
are stacked. In addition, on top of this first lead 8N J21, as shown in FIG. 1 (B), the insulated rattan 11 is laminated with a part left unremoved, and on top of that, as shown in FIG. 1 (H). ), the second lead wire N422 is laminated.

Kokote, 1st and m 2 (7) IJ-to mrt
i [1,422 is printed so that the wiring patterns are shifted from each other by 172 pitches. Further, the electrode portion 4I formed near the end of the substrate 1 is the lead wire layer 4 of W2.
It is formed at the same time by the same process as No. 22. In other words, the electrode portion 4I and the second lead wire layer 422 are generally formed by printing on one surface of a thick Au film and performing a photolithography process and an etching process while referring to the position of the first lead wire layer 421. patterning with high precision and high density.

Furthermore, as shown in FIG. 311(d), a protective glass N5 is laminated on the electrode portion 41 and the second lead wire N422, as in the conventional case, to protect the electrodes and the like.

Through the steps described above, a common electrode layer 2. Glass N3. Fill separate electrode layer 4 (fl!
Pole valve portion 411 and second lead wire [421, 42
2) and the protective glass layer 5 are sequentially laminated, the end surface of the substrate is cut at the position indicated by the arrow AB in the figure. This cutting position is above the electrode portion 41. Therefore, on this updated end surface, the common electrode layer 2 and the first
One layer of the electrode portion 41 (individual electrode layer 4) led from the second lead wire N421.degree. 40 is exposed, and the heating resistor 6 is formed on this end surface. Further, the heating resistor 6 is separated by laser cutting 7 or the like in accordance with the pitch of the individual electrode layers 4. Furthermore, a protective and wear-resistant layer is formed on the heating resistor 6.

As is clear from the above description, the state of the electrodes appearing on the updated end face (ii! position) is the same as that in FIG. 4 above, except for the electrode density. Therefore, it is possible to obtain an edge-type thermal head that has high resolution and various characteristics similar to those of conventional devices, such as high thermal efficiency and good print quality.

In this way, when the lead wire portion 42 of the individual electrode layer 4 has a two-layer structure, the wiring density increases as the resolution of the individual electrode layer 4 increases because the electrode portion has a small area near the end surface of the substrate. 41, the area that requires high-density patterning is reduced, and the yield during manufacturing can be improved. In addition, in the lead wire portion 42, the wiring density per layer of the first and second lead wires [421, 40 is low, so when a driver IC chip or the like is mounted on the board, there is a margin in the wiring pattern. This makes connection with these devices easier.

In the above description, the number of layers of the lead wire portion 42 is not limited to two layers. For example, the number of layers of the lead wire portion 42 is not limited to two layers.
If 1 is 3 [Q structure, the wiring density per - layer is 173
It can be done.

2 and 3 are configuration diagrams showing other embodiments of the end face type thermal head of the present invention. In FIG. 0, the jf
Components similar to those in FIG.

The embodiment shown in FIG. 1 and 2 includes a driver IC chip group 91. which drives the heating resistor 6. ! This figure shows the case where they are integrally mounted on a 2tt board 1. Here, driver IC
Chip #tsu1. ! 2 is each lead wire/11421°422
The driver ICs are provided to drive the heating resistors 6 through the driver ICs installed in the rear row on the board 1.
The chip group 91 is connected to the first lead layer 421, and the driver IC chips #! 2 is 12
is connected to the lead wire layer 422 of. Therefore, the heating resistors 6 arranged in the - column are the driver IC chips #! I
, 92 alternately, and each is driven independently.

Here, since these driver IC chips 9N and 92 are serially connected between their built-in shuffle registers, the recorded data corresponding to the heating resistor 6 is transmitted to the driver IC chip group 1°92 for each bit. are distributed and input to the shift registers.

In this way, if the lead wire portion 42 connected to driver IC chip #11.92 is made of 2Nfla, each driver IC chip #11. ! The density of wiring, connection pads, etc. around No. 2 can be halved.

In the embodiment shown in FIG. 3, the end surface forming the heating resistor 6 is polished obliquely. in this way.

By obliquely polishing the end surface of the substrate 1, it is possible to reduce the effect of chipping that occurs during polishing, improve the yield during II manufacturing, and reduce the contact area with recording paper etc. to increase printing pressure. Can be made smaller.

【Effect of the invention〕

As explained above, in the edge-type thermal head of the present invention, a plurality of electrode layers serving as individual electrode layers or a common electrode layer are arranged on a substrate such that they face each other with a glass layer serving as an electrical insulation layer and a thermal resistance layer interposed therebetween. In an edge-type thermal head in which layers are sequentially formed on one surface and heating resistors are formed on the exposed end surface of each electrode layer, the individual electrode layers are connected to the electrode portion near the end surface of the substrate and the lead wire portion at the center of the substrate. The lead wire portion is constructed from two lead wire layers laminated with an insulating layer in between, and the lead wire pattern devices in the 2N lead wire layers are shifted by 1/2 pitch from each other. Since each lead wire pattern is led to one layer of electrodes, as the resolution increases, the wiring density increases only in the small area of the electrodes near the edge of the substrate, which eliminates the need for thick film as in the past. Even if electrodes are used, it is possible to realize an end-face type thermal head with a simple configuration that can achieve high yield and high resolution.

[Brief explanation of the drawing]

FIGS. 1 to 3 are block diagrams showing one embodiment of the edge-type thermal head of the present invention, and FIG. 1I4 is a block diagram showing an example of a conventional edge-type thermal head. 1...Substrate, 2...Common electrode layer, 3.
...Glass layer, 31...Insulating glass layer,
4...Individual electrode layer, 4I...Electrode portion, 4T...Lead wire portion, 421.422...
...First and second lead wire layers, 5...Protection glass layer, 6...Heating resistor, 7...
・Laser cut. 8...Protective and wear-resistant layer, 51. S...
...Driver IC chip group. Figure 1 C) (B) Figure 1 C) (=) Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A plurality of electrode layers serving as individual electrode layers or a common electrode layer are sequentially stacked on one surface of the substrate so as to face each other with a glass layer serving as an electrical insulation layer and a thermal resistance layer interposed therebetween, and each electrode layer is exposed. In an end-face type thermal head in which a heating resistor is formed on the end face of the substrate, the individual electrode layer is divided into an electrode part near the end face of the substrate and a lead wire part at the center of the board. It is composed of two stacked lead wire layers, and the lead wire pattern devices in these two lead wire layers are shifted by 1/2 pitch from each other, and each of these lead wire patterns is guided to the electrode portion of one layer. An end face type thermal head characterized by: