JPS6038178A - Thermal head - Google Patents

Abstract

PURPOSE:To make the character printed to heat-sensitive paper easily viewable by securing the current capacity of a common electrodes, by connecting an electrode reinforcing plate connected to the common electrode to the side surface part of a ceramic base plate. CONSTITUTION:One side of a ceramic base plate 9 is beveled and a common electrode 4 and a separated electrode group 5 are printed while a part of the common electrode 4 is formed onto the beveled oblique part 9a and the ceramic plate 9 is adhered onto an alumina heat dissipating plate 2. A part of a polyimide base 6 having a reinforced electrode pattern comprising copper is cut to expose the reinforced electrode pattern and a gold plated copper plate 7 is adhered while a gold ribbon 8 is fusion bonded to the copper plate 7 under pressure to be adhered onto the heat dissipating plate 2 in the vicinity of the beveled side of the ceramic base plate 9. In the next step, the gold ribbon 8 on the copper plate 7 is attached to the gold pattern of the common electrode 4 on the oblique part 9a by a pressure fusion bonder.

Description

[Detailed description of the invention] [Technical field of invention] This invention is used for facsimile and printer recording.

The present invention relates to a thermal head used as a display device, and relates to a thermal head whose recording power supply circuit is reinforced.

[Prior art]

Conventionally, there have been devices of this type as shown in FIGS. 1 and 2. In FIGS. 1 and 2, ■ is a ceramic substrate, 2 is a base that supports this ceramic substrate 1, 3 is a group of heating elements printed, vapor-deposited, or sputtered on the ceramic substrate 1, and 4 is on the ceramic substrate 1. A common electrode 5 is printed, vapor-deposited, or sputtered in the same manner as in FIG.

When manufacturing this thermal head, it is placed on a ceramic substrate 1 supported by a base 2 such as an aluminum heat sink, as shown in FIG.
) As shown in the enlarged view, one heating element 3a, 3b, .
A heating element group 3 consisting of... is printed, and each heating element 3
A conductive pattern of the common electrode 4 is printed so that one ends of a and 3b are connected to the common electrode 4. Next, the other ends of the respective heating elements 3a and 3b are the respective separation electrodes 5a of the separation electrode group 5, respectively.

A conductor pattern of the separated electrode group 5 is printed so as to be connected to the electrode group 5b. A heating element group 3 is generally mounted on the ceramic substrate l.
When creating the common electrode 41 and the separated electrode group 5, which are composed of conductor patterns, there are two methods: a thick film permeable method and a thin film manufacturing method. In this description, the thick film manufacturing method is used as the manufacturing method.

Next, the operation will be explained.

When a recording current is passed through the common electrode 4 to cause each of the heating elements of the heating element group 30 to generate heat, the potential of the separate electrode group 5 connected to the other end of each heating element 3a, 3b+, . . . of the heating element group 3 increases. By appropriately selecting and setting , current can be passed through any heating element of the heating element group 3 . Therefore, the Joule heat generated in the heating elements can cause the thermal paper on the heating element group 3 to develop color. The current capacity at this time is usually 10 mA to 10 mA per heating element-element.
It is driven with a current capacity of about 100 mA.

In conventional thermal heads of this type, the recording current required to generate heat in the heating element group is relatively large, so the pattern width on the common electrode side had to be wide in order to ensure the current capacity on the common electrode side. . Therefore, there is a drawback that it cannot meet the requirement of installing the heating element group of the thermal head at the end of the ceramic. In addition, if the pattern width is made narrower and the pattern thickness is increased in consideration of this point, the common electrode will have a higher plane height than the heating element group, resulting in disadvantages such as the pressure of the pressure roll that presses against the heating element group not matching. was there.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and a group of heating elements is installed near the edge of a ceramic substrate, and a common electrode is installed between the edge of the substrate and the group of heating elements. By providing a pattern and attaching an electrode reinforcing plate having an electrode reinforcing pattern connected to the common electrode pattern to the side surface of the ceramic substrate to ensure the current capacity of the common electrode, it is possible to print on thermal paper using the electrode reinforcing pattern. An object of the present invention is to provide a thermal head that allows characters to be observed immediately after being recorded.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

3 to 5 show a thermal head according to an embodiment of the present invention, and in FIG. 3, reference numeral 6 has a thickness of about 50 μm and has a reinforcing electrode pattern (not shown) made of copper therein. Polyimide base, 7 is polyimide base 6
A gold-plated copper plate of about 70 μm is attached to the polyimide base 6 by scraping off a part to expose the reinforcing electrode pattern and adhering it thereto. It is a gold ribbon of approximately 25 μm.

Further, in FIGS. 4 and 5, reference numeral 9 denotes a ceramic substrate whose edges are slitted, and has an inclined portion 9a on the side surface of the slitted end, and 2 is a ceramic substrate 9.
and a base such as an aluminum heat sink that supports the polyimide base 6, 3 is a heating element group installed near the slit end of the ceramic base @ 9, 4 is a common electrode, and 5 is a separate electrode group. , one end of the heating element group 3 is connected to the common electrode 4, and the other end of each heating element of the heating element group 3 is connected to each separation electrode of the separation electrode group 5.

Since the operation of this thermal head is the same as that of the conventional device, the explanation will be omitted, and the method of manufacturing the two thermal heads will be explained.

Thickness 1. One side of the ceramic substrate 9 of Ots is 0 from the top surface.
．． 5fi Shiritori. Next, from the edge of one side of the ceramic substrate 9, a common electrode pattern and a separation electrode pattern are printed with IN as the common electrode width, and the common electrode 4 is printed.
and constitute a separate electrode group 5.

As a result, a part of the common electrode 4 is formed on the slanted portion 9a of the ceramic substrate 9.

Next, the heating element group 3 is formed at a position 1.5 mm from the edge of one side of the ceramic substrate 9.

In the case of the method of the invention, a thick film printing method was used for this production.

Therefore, the common electrode 4 and the separate electrode group 5 are conductive patterns using thick film gold paste. Next, the ceramic substrate 9 is fixed in a predetermined position with adhesive on the base 2 made of an alumina heat sink, and a polyimide base 6 having the reinforcing electrode pattern shown in FIG. 3 and serving as an electrode reinforcing plate is attached. As shown in FIG. 5, the ceramic substrate 9 is bonded onto the base 2 in the vicinity of one slit side. Next, the gold ribbon 8 attached to the gold-plated copper plate 7 is attached to the gold pattern portion of the common electrode 4 on the slit inclined portion 9a of the ceramic substrate 9 using a thermocompression bonder. Furthermore, although not shown, the mounting plate for the gold ribbon 8 is molded with epoxy resin to protect the gold ribbon 8.

In the thermal head of this embodiment as described above, the current capacity on the common electrode side is ensured by the reinforcing electrode pattern of the electrode reinforcing plate 6, so the pattern width of the common electrode pattern can be made small, and thereby the heating element group We were able to create a so-called super-edge type thermal head that was installed at the edge of the substrate.

Moreover, in this case, since the pattern thickness of the common electrode pattern is not increased, the plane height of the common electrode will not be higher than the group of heat generating elements, and the problem of inconsistent pressure of the press rolls will not occur.

Furthermore, since the common electrode and the reinforcing electrode pattern are connected using the gold-plated copper plate 7 and the gold ribbon 8, the reinforcing electrode pattern made of copper and the gold-plated copper plate are connected, and the gold-plated copper plate and the gold ribbon are connected. Stable and reliable connection,
The equipment is highly reliable.

Note that in the above embodiment, explanation of the wear-resistant layer for protecting the common electrode 42, the separation electrode 5, and the heating element group 3 is omitted, but it may be provided. Further, although the gold ribbon thermocompression bonding method was used to connect the common electrode 4 and the polyimide base 6, which is the common electrode reinforcing plate, a wire bonding method or a special soldering method may be used instead.

〔Effect of the invention〕

As described above, according to the thermal head according to the present invention, the common electrode and the electrode reinforcing plate having the reinforcing electrode pattern are connected using the side surface of the ceramic substrate, so that the current capacity of the common electrode is sufficiently secured. 1. Even if an electrode reinforcing plate is attached near the heating element, the thermal paper passing over the heating element will not be damaged.1. Moreover, various effects such as not getting in the way of the rollers can be obtained.

[Brief explanation of drawings]

FIG. 1 [al (bl is a plan view and a partially enlarged view of a conventional thermal head, FIG. 2 is a side view of a conventional thermal head, and FIG. 3 is a method for manufacturing a thermal head according to an embodiment of the present invention) FIG. 4 is a plan view of the thermal head according to an embodiment of the present invention; FIG.
FIG. 5 is a side view of the thermal head. DESCRIPTION OF SYMBOLS 1...Ceramic substrate, 2...Base, 3...Heating element group, 4...Common electrode, 5...Separate electrode group, 6
... Polyimide base (electrode reinforcing plate), 7... Gold plated copper plate, 8... Gold ribbon, 9... Ceramic board. In the drawings, the same reference numerals indicate the same or equivalent parts. Agent Masuo Oiwa

Claims (1)

[Claims] (1) A ceramic substrate, a group of heating elements installed near one end of the ceramic substrate, and a common electrode pattern exposed between the end of the ceramic substrate and the group of heating elements. and an electrode reinforcing plate having a reinforcing electrode pattern installed on a side surface of the ceramic substrate in close proximity to the common electrode pattern and connected to the common electrode pattern.