JPH0483652A - Thermal head and electronic equipment using it - Google Patents

Abstract

PURPOSE:To form a smooth and accurate heating element and electrode pattern to obtain a thermal head realizing a high-density pattern by a method wherein an edge part at which a C face is in contact with a side face and an edge part at which the C face is in contact with an end face are also chamfered or rounded in a circular form, and a glass glazed layer is provided from the end face to the side face provided with the chamfered part. CONSTITUTION:In this thermal head, an edge part at which a C face 11a is in contact with a side face 11b and an edge part at which the C face 11a is in contact with an end face 11c are chamfered. A glass glazed layer 12 is provided from the end face 11c of a substrate 11 to the side face 11b provided with the C face 11a In this manner, the both edge parts of the C face 11a are cut off. In this structure, a surface tension of a fused glass can be reduced at the edge parts. Therefore, the glass glazed player 12 is prevented from being thinned or disconnected at these parts, and a surface smoothness is ensured. On these parts, a smooth and accurate pattern can be formed, and a high-density pattern can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is useful in thermal transfer recording systems.

Conventional thermal recording technology is easy to maintain, produces low noise, and produces high-quality images, so it is used as the print recording section of many electronic devices such as facsimiles, word processors, and computer printers. .

Among these, serial type thermal heads are used in word processors and small printers.

An example of a conventional thermal head used in a serial printer will be described below with reference to the drawings. FIG. 6 shows a cross-sectional configuration diagram of a conventional thermal head. In FIG. 6, 61 is a substrate whose main component is alumina, and 62 is a glass glaze layer which serves to cover the heat insulating layer and the irregularities of the substrate 61 and smooth the surface. 63 is a heating element, 64 is an electrode film, and 65 is a storage! ! ! membrane, 6
6 is a Ni solder plate for taking out the electrode.

The operation of the thermal head configured as described above will be explained below. In FIG. 6, the heat generating section generates heat by applying a printing pulse to the zero heat generating element 63 configured on the substrate 61 on which the glass glaze layer 62 is formed, and at the same time, the base 61 is connected to the transfer paper and the ink ribbon. Printing is performed by moving the top.

However, in the thermal head with this configuration, the heating element 6
The protective film 65 on 3 is concave and makes poor contact with the paper, making it difficult to print clearly on paper with a rough surface (hereinafter referred to as rough paper), and making it difficult to form the glass glaze layer 62 thinly. Because of this difficulty, it was difficult to perform high-speed drive due to heat accumulation.

As a countermeasure for this, as shown in FIG. 7, the edge portion where the main plane (hereinafter referred to as the side surface) 71a and the end surface 71b intersect is chamfered (the surface formed by this processing is hereinafter referred to as the C surface 71c). A thermal head having a structure in which a glass glaze layer 72 and a heating element 73 are formed on the C-plane 71c (hereinafter, a thermal head having this structure is referred to as a C-type thermal head) has been devised. In this configuration, since the area of the heat generating part is small, the pressure of the heat generating part against the paper can be made thicker (as a result, the printing quality on rough paper can be improved), and since the area of the zero surface 71c is small, the glass glaze layer 72 can be relatively Since the structure can be made thin, the driving speed can be increased.In FIG. 7, 74 is an electrode film, 75 is a protective film, and 76 is a Ni solder plate for taking out the electrode.

Problems to be Solved by the Invention In the conventional C-type thermal head, the heating element 73 is connected to the substrate 71.
The C side? It is configured in the lc section, and the electrode Wl! 74 and the pattern of the heating element 73 are formed near the zero surface 71c, the side surface 71a on the side where the zero surface 71c is formed, and the end surface 71b. In this way, in order to form continuous patterns on 3,000 planes that are not on the same plane, it is desirable that the connecting parts be connected in a smooth pattern. 71a, 0
At the edge portions 7A and 7B where the surface 71c and the end surface 71b intersect, the glass glaze layer 72 becomes thinner or breaks due to the surface tension of the molten glass during glaze formation, so that unevenness of the substrate 71 tends to remain on the surface. . For this reason, when a high-density pattern is formed, deformation or breakage of the pattern is likely to occur, leaving room for improvement in pattern formation in this area.

The present invention solves the above-mentioned problems, and aims to provide a thermal head that can form clear and detailed heating element and electrode patterns, and can realize high pattern density. be.

Means for Solving the Problems To achieve this object, the thermal spatula F of the present invention has the following features:
The edge portion where the C surface and the side surface, and the C surface and the end surface intersect, is also chamfered or rounded into an arc shape, and a glass glaze layer is formed from the end surface to the side surface on which the chamfer is formed. .

Effect: With this configuration, the corners of the substrate at the edge portions where the C plane and the side surface and the C plane and the end plane intersect, which are pattern connection parts, are substantially reduced, that is, the curve of the substrate becomes smooth. This eliminates thinning and discontinuity of the glass glaze layer in this area, making it possible to prevent surface irregularities. Therefore, it is possible to form a smooth and fine pattern in this part, and high density can be realized.

Example (Example 1) Hereinafter, a thermal head according to an example of the present invention will be described with reference to the drawings. FIG. 1 shows a cross-sectional structural diagram of a thermal head in an embodiment of the present invention. In FIG. 1, reference numeral 11 denotes a substrate mainly composed of alumina, which includes a 0 surface 11a, a side surface 11b, and an 0 surface 11a and an end surface 11.
Chamfering is performed on the part where c intersects. 1
2 is a glass glaze layer, 13 is a heating element, 14 is an electrode film,
15 is a protective film, and 16 is a Ni solder plate for taking out the electrode. As shown in FIG. 1, a glass glaze layer 12
is formed from the end surface 11C of the base FiII to the side surface 11b on the side where the 0 surface 11a is formed.

The operation of the thermal head constructed as described above will be explained below while comparing it with a conventional thermal head (FIG. 7). In the conventional thermal head, 0 side 71
c, side surface 71a (7B in Fig. 7), 0 surface 71a and end surface 7
1b (A in FIG. 7) intersect, the glass glaze layer 72 was thinned or interrupted due to the surface tension of the glass. For this reason, irregularities of the substrate 71 tend to remain on the surface in this part, and pattern abnormalities tend to occur, making it difficult to achieve high density.

On the other hand, in the embodiment of the present invention shown in FIG. 1, the surface tension of the molten glass at the edge portions is will be able to alleviate the Therefore,
It is possible to prevent the glass glaze layer 12 from becoming thin or cut off at this portion, and the smoothness of the surface can be ensured. Since unevenness on the surface can be prevented in this way, it becomes possible to form a smooth and fine pattern in this area, and a high density pattern can be realized.

Regarding printing characteristics, in the conventional thermal head, the glass glaze layer 72 is thinner than necessary at the edge portions (7A and 7B in FIG. 7) on both sides of the 0 surface 71c, resulting in a decrease in thermal efficiency and poor paper quality. Deterioration of dynamic characteristics, etc. had occurred. Regarding this point as well, in the thermal head of this embodiment, the edge portions (IA, 1B in FIG. 1) on both sides of the 0 surface 11a
Since the required amount of glass glaze layer 12 is present in
The printing characteristics can be improved compared to the conventional example.

Furthermore, by adopting the configuration of this embodiment, the edge portion I
Since there are no breaks in the glass glaze layer 12 at A and IB, and the glass glaze layer 12 is continuous from the side surface 11b to the end surface 11c, the thickness of the glass glaze layer on the zero surface 11a can be stabilized. Therefore, variations in print quality between heads can be reduced.

As described above, according to this embodiment, by chamfering the edge portions on both sides of the 0-face 11a again or rounding the edge portions into an arc shape, the glass glaze layer is formed at the edge portions IA and IB on both sides of the 0-face 11a. It becomes possible to prevent surface roughness due to lack of 12. As a result, surface 0 11a
and the edge portion I of the end surface 11c, the 0 surface 11a and the side surface 11b.
Since it is possible to prevent pattern breakage and deformation at A and IB, it is possible to achieve higher pattern density than in the conventional example.

Further, since there is no discontinuity in the glass glaze layer 12 on the zero surface 11a, it is possible to improve thermal efficiency and sliding characteristics, stabilize the thickness of the glass glaze layer 12, and improve printing characteristics.

The important point in Fig. 1 is that the chamfer of the part 7B in Fig. 7 should be shorter than the length of the 0-face 11a and longer than a quarter of the length of the 0-face 11a, and the chamfer of the part 7B in Fig. 7 should be shorter than the length of the 0-face 11a. Saha 0 side 11a
The goal is to make it shorter than one-fourth of that. By adopting this configuration, the necessary glass thickness is secured in the IB portion, and the zero surface 11a of an appropriate length is secured, so that the above-mentioned characteristics can be fully brought out.

(Example 2) Hereinafter, a second example of the present invention will be described with reference to the drawings.

FIG. 2 shows a cross-sectional structural diagram of a thermal head in a second embodiment of the present invention. In Figure 2,
21 is a substrate mainly composed of alumina, processed so that the angle of the 0 side 21a is 45 degrees with respect to the side surface 21b, and the 0
Chamfering processes 21d and 21e are performed on the edge portions where the surface 21a and the side surface 21b, and the 0 surface 21a and the end surface 2]c intersect. 22 is a glass glaze layer, 23 is a heating element, 24 is an electrode film, 25 is a protective film, and 26 is Ni Hada plating for taking out the electrode.

FIG. 3 shows a schematic diagram of a printing device constructed using the thermal head of this method. In FIG. 3, 31 is a platen, 32 is a transfer paper, 33 is a thermal head in this embodiment, 34 is a heat generating section, 35 is an ink ribbon, 36 is an ink ribbon take-up roller, 37 is a side surface, and 3 is an end surface. It is.

The operation of the printing apparatus configured as described above will be explained with reference to FIG.

As shown in FIG. 3, the thermal head 33 with the heating element 34 formed on the C side is supported so that the 0 side is parallel to the transfer paper 32. Therefore, the end face 38 and the side face 37 form an angle of approximately 45° with respect to the transfer paper 32, and the ink ribbon conveyance system such as the ink ribbon 35 and the ink ribbon take-up roller 36 is symmetrical with respect to the heat generating part 34. Can be placed in position.

The angle that the surface in the advancing direction makes with the paper surface when viewed from surface 0, and the peeling angle of the ink ribbon (preferably as large an angle as possible) affect printing quality. Therefore, when performing reciprocating printing, the heating element It was necessary to make the head configuration around the heating element 34 and the ink ribbon transport system symmetrical with respect to the heating element 34. In the conventional thermal head (FIG. 7), since the angle of the C surface 71C with respect to the side surface 71a is usually 45'' or less, the angles of the end surface 71b and the side surface 71a with respect to the plane of the paper are different.

Therefore, when performing reciprocating printing, when printing is performed while the head moves in the side direction when viewed from surface 0 (hereinafter referred to as the outward path), the angle between the end surface 71b and the paper surface 71a is 45 degrees or more, and the ink The ribbon peeling angle can be increased, but when printing in the opposite direction (hereinafter referred to as the return path), the angle between the side surface 71a and the paper surface is 45° or less, and the ink ribbon peeling angle is also 45''. It becomes below.

Therefore, when performing back-and-forth printing using the conventional thermal gutter, the print quality on the outward and return passes may differ.

In the thermal head of this embodiment, since the 0 side is configured to be at 45 degrees to the side surface 37, the side surface 37 and the end surface 38 are at an angle of 45 degrees to the side surface 32 of the transfer paper, as shown in FIG.
5 degrees, and the ink ribbon conveyance system, such as the ink ribbon stripping angle, can also be made bilaterally symmetrical with respect to the heat generating section 34.

Therefore, the conditions can be made the same when printing while the thermal gutter 33 moves to the right and when printing while moving to the left, making it possible to maintain the same printing quality on the outward and return passes.

As described above, according to this embodiment, by configuring the 0 side so that it is at an angle of 45 degrees with respect to the side surface 37, it is possible to perform reciprocating printing without degrading the printing quality, and therefore high-speed printing can be realized. Become.

(Embodiment 3) Hereinafter, a third embodiment of the present invention will be described with reference to the drawings.

FIG. 4 is a diagram showing a third embodiment of the present invention, and is a diagram of an electrode pattern formed on the main plane of a substrate of a thermal head. In FIG. 4, 41 is the substrate used in (Example 1) and (Example 2), 42 is a heating element, 43 is the 0 side, 44 is an electrode wiring pattern, and 45 is an electrode pattern for wiring extraction (hereinafter referred to as (referred to as the bonding part).

There is a limit to the interval between such bonding parts 45,
If the interval is too small, short circuits between adjacent electrodes are likely to occur due to positional displacement or protruding solder during bonding. For this reason, the heating element density of conventional thermal heads has been limited by bonding properties with external leads, and in order to increase the heating element density, the number of bonding parts 45 increases, so the substrate size must be increased. had to respond in this way.

In the head of this embodiment, as shown in FIG. 4, the rows of electrode bonding portions 45 are arranged on two sides, and every other electrode is arranged in a different row. As a result, compared to the case where the bonding parts are arranged in a row, the distance between the bonding parts can be increased, and the bonding density can be reduced. Therefore, even if the heating element 42 of the thermal head becomes denser, it can be handled without increasing the substrate size.

Next, FIG. 5 shows a cross-sectional configuration diagram of a bonding part in an embodiment of the present invention. In FIG. 5, 51 is the substrate used in (Example 1) and (Example 2), 52 is a glass glaze layer, 53 is an electrode film, 54 is a Ni solder plate formed on the bonding part, and 55 is an insulating material. It is a photosensitive resin that covers the electrode pattern on the side surface other than the bonding part. The holes in the bonding area are made by photoresist processing.

In the bonding process, after positioning, thermocompression bonding is performed to connect the Ni solder plating 54 and the external electrode. At this time, if the pitch of the bonding portions is small, a short circuit due to solder protrusion or positional deviation may cause unnecessary contact between the external lead side electrode and the head side electrode backcoup. In the head of this embodiment, by surrounding the bonding portion with the insulating material 55 as described above, it becomes difficult for melted solder to flow out from the bonding portion. In addition, by covering the electrode pattern other than the bonding part with the insulating photosensitive resin 55, it is possible to prevent short circuits due to solder protrusion, and furthermore, it is possible to prevent unnecessary contact between the external lead side electrode and the head side electrode. .

Furthermore, Ni solder plating 54 is applied only to the bonding part by electrolytic plating, but by covering the parts other than the bonding part with insulating photosensitive resin 55 as described above, no special masking process for plating is performed. This means that it will be possible to perform the metsuki.

In the embodiment shown in FIG. 3, an insulating photosensitive resin 5 is used.
5 was used, but heat-resistant resin such as polyimide may be vapor-deposited, or glass paste or the like may be printed and fired.

Effects of the Invention As described above, the present invention chamfers the edge portion where the end surface and the crown surface of a highly thermally conductive substrate intersect, and further chamfers or arcuates the edge portions where the chamfer and the main plane and the chamfer and the end surface intersect. By rounding the part, it is possible to form a smooth and fine pattern even on the chamfer, making it possible to realize an excellent thermal head that can perform high-density printing.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a thermal head according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view of a thermal head according to a second embodiment of the present invention, and FIG. 3 is a cross-sectional view of a thermal head constructed using this thermal head. FIG. 4 is a schematic diagram of a printing device according to the third aspect of the present invention.
FIG. 5 is a sectional view of the bonding part, and FIGS. 6 and 7 are sectional views of the conventional thermal head. . 11...Substrate, 12...Glass glaze layer, 13...Heating element film, 14...Electrode film, 15...Protective film , 16...Ni
Solder peck. Name of agent: Patent attorney Shigetaka Awano and 1 other person @ 1 Figure 2

Claims (3)

[Claims] (1) A first chamfer is applied to the edge portion where the end surface and the main plane of the highly thermally conductive substrate intersect, and a second chamfer or A thermal head in which an edge portion is rounded into an arc shape, a glass glaze layer is formed from the end face to the main plane via a chamfered portion, and a heating element is provided on the glass glaze layer of the first chamfered portion. (2) Claim (
1) The thermal head described. (3) An electronic device using the thermal head according to claim (1) or (2) in its printing section.