JPS5851169A - Thermal head - Google Patents

Abstract

PURPOSE:To obtain a thermal head with a system in which marks of regularity are provided to electrodes arranged in large numbers and thereby defective positions can be quickly recognized with lesser malinspection in an inspection process and defective positions can be easily detected and repaired in a short time in a correcting process. CONSTITUTION:A thermal head for photo lithographyis made up of a heating resistor 2, a common electrode 3, and an electrode 4, and an angular notch is formed at the end of fifth electrode, for example. The 5th, 15th, 25th,... notches are provided upwardly as shown by 6 in Fig., and 10th, 20th, 30th,... notches are provided downwardly as shown by 7 and 8 in Fig. In an inspection process, the electrode with the mark X representing disconnection place can be easily judged to be 11th electrode next to 10th one. Even in the correction process, defective positions can be easily detected in a short time. For the notches at the end portion of the electrodes, varuous marks other than the exemplified ones may be used and their positions may be properly selected.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal head equipped with a heating resistor for recording on thermal recording paper.

As a part of the thermal head is shown in FIG. 1, heat generating resistors 2 are arranged parallel to each other once in the longitudinal direction (in the horizontal direction in the figure) on a ceramic substrate 1.
There is a structure in which one end of each heating resistor 2 is connected to the common electrode 3i, and the other end of each heating resistor 2 is connected to the corresponding electrode 4. The upper part of the heating resistor 2 is coated with a 5i02 film to prevent the resistance from increasing due to oxidation of the heating resistor 2, and a wear-resistant film is coated on top of it to protect the heating resistor 2 from contact abrasion with thermal recording paper. Layer 5 is coated.

In addition, as shown in FIG. 2, there is a structure in which the electrodes 4 are divided into blocks by a uniform number.
It is the same as shown in the figure.

Such a thermal head has a common electrode 3 and a south pole 4.
Connect the drive circuit and operate it. That is, a thermal recording paper is brought into contact with the l1otJ' wear layer 5 on the upper part of the heating resistor 2, and a pulsed current is passed between the common electrode 3 and a desired electrode 4 to cause the desired heating resistor 4 to generate heat, thereby causing the heating resistor 4 to generate heat. After shaking that part for one minute, the thermal recording paper is moved t in a direction perpendicular to the arrangement direction of the heating resistors 2 (in the vertical direction in the figure), and the heating resistors 4 develop a color in a direction +a1. By repeating this operation, characters and images can be recorded on the thermal recording paper.

By the way, the heating resistor 2 of such a thermal head,
The common electrode 3 and the electrode 4 are formed by photolithography. The number of heating resistors 2 depends on the recording density and the recording 'l' M and G. For example, the recording density is 8 dots/1 Il11.
, when the recording width is A4 size (216 squares), the number of heating resistors 2 is 1728.

As a result, in a thermal head with a structure as shown in Figure 1, the same number (1728) of electrodes 4 with the same pattern are lined up, and in a thermal head with a structure as shown in Figure 2, there are divided blocks. (e.g. 3)
It is a concern that two electrodes 4 with the same pattern are lined up.

One thermal head manufacturing process includes the Antarctic inspection process and modification process. In the pre-process, defective parts such as disconnections or short circuits are discovered by visual inspection using a stereomicroscope or by a resistance value measuring device, and the defective parts are corrected by wire bonding or laser trimming in the subsequent repair process.

However, in a structure in which dozens or hundreds of electrodes with the same pattern are lined up as shown in Figure 1, and even more so in a block structure in which dozens of electrodes in the same pattern are lined up as shown in Figure 2. However, when inspecting a large number of the same number of turns, your eyes get tired and you make inspection mistakes. Even if you find a defective part, it takes time to identify its location. Difficult and long time to discover during correction process 1
There are problems such as requiring □ t11.

A (The invention has been made in view of the above problem, and it reduces the number of inspection errors when inspecting thermal radars having a large number of identical electrode patterns, shortens the inspection time, and improves the accuracy in one correction process. The object of the present invention is to provide a thermal head structure, particularly an electrode slide structure, which can easily rediscover defective parts and shorten the time for correction.

The present inventor has proposed that a thermal head with a large number of small and poles arranged in the same pattern can be certified as 4th to 1st in a specific city by placing marks in a predetermined number of units on or in the vicinity of the mark. It is intended to achieve the stated purpose easily.

The present invention will be explained in detail below using examples.

FIG. 3 is an enlarged view of the conventional electrode end portion (portion A surrounded by chain dots in FIG. 2) of one block of the thermal head shown in FIG. 2.

Several dozen electrodes 4 having the same pattern are arranged.

The fourth figure is a diagram showing an embodiment of the present invention, and is an enlarged view of part A in FIG. 21, like FIG. 3. In this embodiment, a rectangular notch was provided at the end of the electrode for every five ports.

Furthermore, in this example, 5, 15, 25. ...The notches of the main mouth are provided in two directions as shown in the figure, as shown in 6.]0. 20
゜30...The notches of the main mouth are provided in the downward direction G in the figure as shown in 7 and 8.

In the conventional jelly shown in Fig. 3 and the present embodiment shown in Fig. 4, it is assumed that there is a disconnection at the X mark in the figure. During the inspection process, if you inspect the electrodes from the top of the diagram while looking at the electrodes in Figure 3, you will not only find it easy to strain your eyes since the same pattern is repeated in the electrodes in Figure 3, but you will also find a disconnection marked with an X. In this case, in order to identify whether it is the electrode at that position or the electrode at the main entrance, it is necessary to count sequentially from the upper electrode 9, which is time consuming and may result in mistakes such as misidentifying the position of the % pole where the wire is disconnected by several sous. It becomes easier. On the other hand, in the embodiment shown in FIG. 4, it can be easily determined from the shape of the notch that the electrode having the notch 7 is the 10th electrode, and the electrode with the disconnection point marked
Since it is the next electrode after the 0th electrode, it can be easily determined that it is the 11th electrode.

In other words, in the example shown in Fig. 4, the distance is 5 points, and
There are different marks for the 1st and 10th positions, so there is a disconnection.
The certification of υF9f can be done easily by first determining the 10th place using the 10 unit mark, and then determining the 1st place using that mark as a reference and, if necessary, also using the 5 unit mark as a reference.

In addition, in the repair process, it is necessary to install a wire bonder or laser trimming device to the defective part found in the inspection process, or in the case of Fig. 3, to find the defective part F91, it is necessary to count sequentially from the top. In the case of the fourth worst case, this embodiment, it is possible to easily find the defective part in a short period of time, as described in the inspection process, whereas it takes a long time to conduct the process.

The notch at the end of the electrode in this embodiment is an example of a mark, and other marks such as ridges may be used. For example, the notches or protrusions can be provided with regularity of the shaft, such as in even number positions, odd number positions f'& -5 water wheel positions, and in units of 10.

The notch protrusion is limited to the end of the electrode, and may be provided at a position a certain distance away from the end. As other marks, for example, letters, specific symbols, or figures may be provided on the electrode or the substrate near the electrode with regularity as described in 1.

As described in detail above, the present invention has a large number of arranged electrodes (regular marks), which reduces the delay in identifying the location of a defective part in one inspection process, reduces inspection errors, and reduces the number of errors in the correction process. In this way, it is possible to achieve a thermal head in which it is easy to rediscover defective parts, and therefore the time for correction can be shortened.

[Brief explanation of drawings]

Figure 1 is a partial plan view showing an example of a thermal head - Figure 2
The figure shows another example of the thermal head. Figure 3 is an enlarged view of part A in Figure 2, which shows the electrode pattern of a conventional example. Figure 4 shows the electrode pattern of an embodiment of the present invention. This is an enlarged view of City A in Figure 2. 2... Heating resistor, 3... Common electrode, 4... Electrode, 6°7.8... Notch 1, Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] (1) A thermal head characterized in that marks are provided in units of a predetermined number of electrodes arranged in large numbers or in the vicinity thereof.