JPH0482751A - Thermal head and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain an even printing without uneven density by a method wherein an inclined surface part is formed at an end of an insulation substrate while a heating resistor is formed at the inclined surface part to obtain an even and sufficient printing pressure when an inclined surface part of a head is so arranged to abut on a platen roller vertically. CONSTITUTION:An insulation substrate 2 is made up of a substrate body part 2a and a partial graze 2b and an inclined surface part 2c of the insulation substrate 2 is formed with a surface of a tapered part 2a2 and the surface of a lower part 2b1 of the partial graze successive thereto. A common electrode 3 which has a common electrode body part 3a extending along a main scanning direction X and a plurality of common electrode connection parts 3b protruding along a sub scanning direction Y is formed on the surface of the substrate body part 2a. Moreover, a plurality of discrete electrodes 4 extending in the subscanning direction Y are arranged on the surface of the insulation substrate 2 in a row along the main scanning direction X and tips 4a thereof are arranged on the surface of the partial graze 2b. Electrode tip parts 3b1 and 4a are connected with a heating resistor 5.

Description

Detailed Description of the Invention A1 Purpose of the Invention (1) Industrial Field of Application The present invention relates to a thermal printer used in a thermal printer, facsimile, etc. as an output device for a word processor, personal computer, etc., and a method for manufacturing the same. Regarding.

(2) Conventional technology Thermal heads have been widely used since they have advantages such as low noise during printing and ease of handling since no developing and fixing steps are required. A thermal head H' shown in FIG. 16 is known as a conventional thermal head.

In FIG. 16, a thermal head H' for performing thermal recording on a thermal recording paper P conveyed along the outer periphery of a platen roller R is provided with a support plate 01. This support plate 01
On the upper surface of the board body 02a, on the right side in FIG.
And an insulating substrate 02 having a partial glaze 02b is attached.

The partial glaze 02b extends in the main scanning direction X (direction perpendicular to the paper surface). A common type Vi! is formed on the surface of the insulating substrate 02. 03 and multiple individual! ff104 is formed, and the common electrode 03 and the plurality of individual electrodes 04 are connected to the plurality of heating resistors 0 formed on the surface of the partial glaze 02a.
Connected by 5. Then, the electrodes 03,0
4, the heating resistor 05, etc. are covered with a wear-resistant layer 06, and the surface of the portion of the wear-resistant layer 06 that covers the heating resistor 05 is used as a printed portion 06a. A printed wiring board 07 is adhered to the left side portion of the upper surface of the support plate 01, and connection wiring 08 is formed on the surface of this printed wiring board 07. This connection wiring 08 is connected to a terminal of a socket 010 via a lead pin 09. An IC is disposed in a portion of the printed wiring board 07 near the insulating substrate 02, and this IC is connected to the wire 0.
11 and 012 are connected to the connection wiring 08 of the printed wiring board 07 and the individual electrodes 04 on the surface of the insulating substrate 02. The IC and wires 011, . 01
2 is sealed with resin 013 and covered with cover 0
Protected by 14.

As described above, the thermal head H' in which the heat generating resistors 05 are arranged in a row on the partial glaze 02a has the heat generating resistors 05
The surface portion of the wear-resistant layer 06 covering the printed portion Q6a
The contact pressure between the heat-sensitive recording paper P on the platen roller R, that is, the printing pressure is increased (paper contact becomes better), and uniform printing can be performed.

3) Problems to be Solved by the Invention By the way, in order to make the printing pressure uniform, it is necessary to press the platen roller R vertically against the surface of the insulating substrate 02 on which the printing portion 06a is provided. Therefore, the printed part 06a, the IC and the wire 0
11,012, the surface of the platen roller R approaches the resin 013 when the platen roller R is pressed against the printing section 06a. IC and wire 01 sealed and protected by the resin 013
The cover 014 is attached to the platen roller R so that parts vulnerable to mechanical shock such as 1.012 are not damaged.
and the resin 013. In this way, in order to dispose the cover 014 between the resin 013 and the platen roller R, the printing portion 06a and the resin 0
13 (distance M in the sub-scanning direction Y) is covered by 01
It was necessary to set the length to allow insertion of 4.

Further, the cover 014 can be omitted, but even if it is omitted, in order to prevent the platen roller R pressed against the surface of the insulating substrate 02 from coming into contact with the resin 013, the printing part 06a and It was necessary to set the distance between the resin 013 and the resin 013 to a predetermined length or more. For this reason, it was not possible to reduce the length between the heating resistor 05 and components susceptible to mechanical shock, such as the IC, so there was a limit to the miniaturization of the thermal head.

However, in facsimiles, thermal printers, and the like, the space in which a thermal head can be placed is limited, so it is advantageous to make the thermal head as small as possible.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a thermal head that can obtain a sufficiently large printing pressure and can be miniaturized.

B1 Refinement of the Invention 1) Means for Solving the Problems In order to solve the above problems, the thermal head of the first invention of the present application has a common electrode extending along the main scanning direction A large number of individual electrodes arranged in rows with their tips facing the common electrode, and heating resistors connecting the common electrode and the tips of the individual electrodes are formed on the surface of an insulating substrate. The thermal head is characterized in that an inclined surface portion is formed at an end of the insulating substrate, and the heating resistor is formed on this inclined surface portion.

Further, the method for manufacturing a thermal head according to the second invention of the present application includes a common electrode extending along the main scanning direction, and a common electrode arranged in a row along the main scanning direction, with a tip end facing the common electrode. A method for manufacturing a thermal head, in which a large number of individual electrodes and a heating resistor connecting the common electrode and the tips of the individual electrodes are formed on the surface of an insulating substrate,
Forming an inclined surface portion at an end of the insulating substrate, forming a resist layer having an opening for forming a resistor in the inclined surface portion, and then forming an individual resistor inside the opening for forming a resistor. The heating resistor is formed by forming the heating resistor, and then firing the individual resistor.

2) Function In the thermal head of the first invention of the present application, an inclined surface portion is formed at the end of the insulating substrate, and the heating resistor is formed on this inclined surface portion.

Therefore, by arranging and using the thermal head so that its inclined surface is in perpendicular contact with the platen roller, a uniform and sufficient printing pressure can be obtained, and uniform printing with even density can be achieved. can get. In addition, the attitude of the thermal head in this arrangement is inclined with respect to the platen roller, and the insulating substrate surface is in an attitude away from the platen roller, so that the insulating substrate surface is in contact with the platen roller (i.e. , the part where the heating resistor is formed), the distance from the platen roller increases rapidly. Therefore, even if a component that is susceptible to mechanical shock, such as an IC, is placed near the heating resistor on the surface of the insulating substrate, there is no risk that the weak component will come into contact with the platen roller and be damaged. , I.C.
Components that are susceptible to mechanical shock, such as wires and bonding wires, can be placed close to the heating resistor at the end of the insulating substrate.

Further, the method for manufacturing a thermal head according to a second aspect of the present application includes forming an inclined surface portion at an end of the insulating substrate, and then forming a resist layer having an opening for forming a resistor on the inclined surface portion. Then, individual resistors are formed inside the resistor forming openings, and then the individual resistors are fired to form the heating resistors. Therefore, by adjusting the thickness of the resist layer before firing and the individual resistors in the resistor forming openings thereof, a heating resistor having a uniform thickness can be formed on the inclined surface portion.

3) Implementation example Hereinafter, the present invention will be described in detail based on the drawings.

Fig. 1 is an overall explanatory diagram of an embodiment of the thermal head of the present invention, Fig. 2 is a perspective view of its main parts, Fig. 3 is an enlarged view of the part shown by the arrow 3, FIG. 4B is a sectional view taken along the line IVB-IVB of FIG. 4A, and FIG. 4C is a sectional view taken along the line rVc-IVC of FIG. 4A.

As shown in FIG. 1, a thermal head H for performing thermal recording on a thermal recording paper P conveyed along the outer periphery of a platen roll R is provided with a support plate 1. An insulating substrate 2 is attached to the surface of the support plate 1 on the right side in FIG. 1 with an adhesive.

As shown in FIG. 3, the insulating substrate 2 has a flat plate portion 2al.
and a ceramic substrate main body part 2a having tapered parts 2&2, and the surface of the tapered part 2L2 is inclined at about 20 degrees with respect to the surface of the flat plate part 2a1. A band-shaped partial glaze 2b is formed on the surface of the substrate body portion 2a, and the surface of the lower portion 2b1 of this partial glaze 2b is continuous with the surface of the tapered portion 2a2. An insulating substrate 2 is constituted by the substrate main body portion 2a and the partial glaze 2b. Further, the inclined surface portion 2c of the insulating substrate 2 is formed by the surface of the tapered portion 2a2 and the surface of the partial glaze lower portion 2b1 which is continuous thereto.

3, 4A to 40, a common electrode body portion 3a extending along the main scanning direction X is provided on the surface of the substrate body portion 2a.
A common electrode 3 having a large number of common electrode connecting portions 3b protruding from the common electrode main body portion 3a in a comb-like shape along the sub-scanning direction Y is formed. The common electrode connection part 3b
A tip portion (that is, a common electrode tip portion) 3bl is formed on the surface of the tapered portion 2a2 of the substrate body portion 2a.

The common electrode body portion 3a is entirely covered with a partial glaze 2b, and the common electrode tip portion 3bl is exposed. Further, on the surface of the insulating substrate 2, a plurality of individual electrodes 4 extending in the sub-scanning direction Y are arranged in a row along the main scanning direction X, and their tips 4a are arranged on the surface of the partial glaze 2b. . As clearly shown in FIG. 3, these individual electrode tip portions 4a are arranged at a predetermined distance in the sub-scanning direction Y from the plurality of common t8ii tip portions 3bl on the inclined surface portion 2c. has been done.

The base end portion (the left end portion in FIG. 1) of the individual electrode 4 has an IC connection terminal 4b (4th A,
(see Figure 4B). The tip portion 3b1.4a of each picture electrode is connected to the inclined surface portion 2 of the insulating substrate 2.
They are connected by a large number of island-shaped heating resistors 5 arranged in rows along the main scanning direction X on c.

As shown in FIGS. 4A and 4B, the surfaces of the picture electrode 3.4 and the heating resistor 5 are covered with a wear-resistant layer 6 made of glaze. The surface of the covered portion is formed as a printed portion 6a that transmits heat to the thermosensitive recording paper P. And this printing section 6a
is substantially parallel to the inclined surface portion 2c.

A printed wiring board 7 is attached to the surface of the support plate 1 on the left side in FIG. 1 with an adhesive, and external connection wiring 8 is formed on the surface of the printed wiring board 7. This external connection wiring 18 is connected to a socket 10 as a drive signal input terminal via a lead wire 9 passing through the printed wiring board 7 at its input end side (left side in FIG. 1). A driving IC is disposed in a portion of the printed wiring board 7 near the insulating substrate 2, and this driving IC is connected to the bonding wires 11 and 1.
2 is connected to the IC connection terminal 4b of the individual electrode 4 and the external connection wiring 8.

The IC and bonding wires 11, 12 are covered with a protective resin 13, and the protective resin 13 is further protected by a cover 14 made of aluminum.

The thermal head H of this embodiment has the above-mentioned symbols 1 to 1.
It is composed of the component indicated by 14 and the driving IC.

Next, a common mold 8 is attached to the surface of the insulating substrate 2 of the thermal head H.
A method of forming i3, individual type @4, and heating resistor 5 will be explained.

As shown in FIGS. 5A and 5B, a common electrode forming layer 3L made of gold or the like is formed on the surface of the insulating substrate main body portion 2a having the flat plate portion 2al and the tapered portion 2a2. A resist layer R1 is formed on the surface of this common electrode forming layer 3L, and then a mask M1 is placed thereon, exposed, and developed using an etching solution. Then, a resist pattern RPI for forming a common electrode as shown in FIGS. 6A and 6B is obtained. When the electrode forming layer 3L is etched next and the resist pattern RPI is removed, as shown in FIGS. 7A and 7B. A common electrode 3 is formed on the surface of the substrate main body portion 2a.

Next, as shown in FIGS. 8A and 8B, a band-shaped partial glaze 2b extending along the main scanning direction X and having a thickness of 40 to 80 μm is formed on the surface of the substrate main body portion 2a. In this case, the partial glaze 2b is formed so as to cover the entire common electrode main body part 3&, and the surface of the lower part 2b1 is continuous with the surface of the tapered part 2a2 of the substrate main body part 2a. The inclined surface portion 2c of the insulating substrate 2 is formed by the surface of the tapered portion 2a2 and the surface of the partial glaze lower portion 2b1.

Next, as shown in FIGS. 9A and 9B, an individual electrode forming layer 4L made of gold or the like is formed on the surface of the insulating substrate 2 so as not to contact the common electrode 3, and then a resist layer R2 is formed on the surface. Form. Then, an exposure mask is placed thereon and exposed, and developed with an etching solution to form a resist pattern (not shown) for forming individual electrodes. Next, when the individual electrode formation layer 4L is etched, the 10A, 1
As shown in Figure 0B, multiple individual ! [!
4 is formed.

Next, as shown in FIGS. 11A and 11B, a resist layer R3 having a thickness of 15 to 20 μm is formed on the surface of the insulating substrate 2 on which the partial glaze 2b, the common electrode 3, and the individual electrodes 4 are formed. Then, a mask M3 is placed thereon, exposed, and developed with an etching solution. Thus, the first
As shown in FIGS. 2A and 12B, a resist pattern RP2 has a large number of resistor formation openings Ho arranged in rows along the main scanning direction X on the inclined surface portion 2c of the insulating substrate 2.
form. Note that the opening H for forming the resistor.

is formed such that the common t8i connection portion 3b and the individual electrode tip portions 4a are arranged therein.

Next, as shown in FIGS. 13A and 13B, the resistor forming material G is applied to the resist pattern R by screen printing or the like.
A strip is printed along the row of the openings HO of P2, and the inside of the openings Ho is filled and dried.

Next, as shown in FIGS. 14A and 14B, the dried resistor forming material G is lapped (ground) to remove a portion above the surface of the resist pattern RP, and an unsintered material is placed inside the opening Ho. Next, the individual resistors 5' are fired at a temperature of 800 to 900 DEG C., and the resist pattern RP2 is removed by combustion.

Then, as shown in FIGS. 15A and 15B, a large number of island-shaped heating resistors 5 are formed on the inclined surface portion 2c of the insulating substrate 2 along the main scanning direction χ, connecting the picture electrodes 3 and 4. be done.

Next, the surface of the insulating substrate 2 on which the picture electrode 3.4, the heating resistor 5, etc. are formed is coated with an anti-wear layer 6. Then, an insulating substrate as shown in FIGS. 4A to 40 is obtained.

The thermal head H constructed using the insulating substrate shown in FIGS. 4A to 40 has a heating resistor 5 as shown in FIG.
The platen roller R is arranged and used so as to be in perpendicular contact with the inclined surface portion 2c on which the platen roller R is formed.

In the thermal head H of the above-described embodiment, the common electrode main body portion 3a arranged along the main scanning direction Therefore, along the surface of the insulating substrate 2 in the sub-scanning direction Y
The dimensions in the sub-scanning direction Y can be made smaller compared to the conventional device in which the scanners are arranged apart from each other.

Although the embodiments of the thermal head and the manufacturing method thereof according to the present invention have been described in detail above, the present invention is not limited to the above embodiments, and is within the scope of the gist of the present invention as described in the claims. It is possible to make various minor design changes.

For example, instead of arranging the common electrode main body part 3a and the plurality of individual electrode tip parts 4a apart in a direction perpendicular to the surface of the insulating substrate 2, it is also possible to arrange them apart in a direction along the surface of the insulating substrate 2. . It is also possible to omit the two-part glaze 2b or to form an underglaze on the entire surface of the insulating substrate 2. Further, the inclined surface portion 2c forming the heating resistor 5 can be formed only from the surface of the tapered portion 2a2 instead of being formed from the surface of the tapered portion 2a2 of the substrate body portion 2a and the surface of the partial glaze lower portion 2b1. . In that case, the common electrode 3 and a plurality of individual electrode tip portions 4a may be formed on the surface of the tapered portion 2a2 so as to be separated in the sub-scanning direction Y.

Further, the angle of inclination of the surface of the tapered portion 2 with respect to the straight surface of the flat plate portion 2 can be set to an appropriate angle other than 20° shown in the embodiment. Furthermore, the present invention can be applied to various thermal heads in which the shapes of the electrodes and heating resistors, and the order or method of forming them are different from those of the above-mentioned embodiments.

C1 Effects of the Invention In the thermal head of the first invention of the present application described above, an inclined surface portion is formed at the end of the insulating substrate, and the heating resistor is formed on this inclined surface portion. Therefore, if the thermal head is arranged and used so that its inclined surface part contacts the platen roller perpendicularly, the contact area between the thermal head and the platen roller is small.
Sufficient printing pressure can be obtained, and printing without density unevenness can be obtained. In addition, the attitude of the thermal head with respect to the platen roller in this arrangement is such that the surface of the insulating substrate other than the inclined surface portion is away from the platen roller, so that the surface of the insulating substrate is in contact with the platen roller (i.e., the heating resistor The distance from the platen roller increases rapidly as the distance from the platen roller increases. Therefore, even if a component that is susceptible to mechanical shock, such as an IC, is placed near the heating resistor on the surface of the insulating substrate, there is no risk that the weak component will come into contact with the platen roller and be damaged. Components that are susceptible to mechanical shock, such as ICs and bonding wires, can be placed close to the heating resistor at the end of the insulating substrate.

Therefore, since the width of the insulating substrate (dimension in the sub-scanning direction Y) can be reduced, it is possible to miniaturize the insulating substrate, that is, to miniaturize the thermal head. Further, the method for manufacturing a thermal head according to a second aspect of the present application includes forming an inclined surface portion at an end of the insulating substrate, and then forming a resist layer having an opening for forming a resistor in the inclined surface portion. Then, individual resistors are formed inside the resistor forming openings, and then the individual resistors are fired to form the heating resistors. Therefore, by adjusting the thickness of the resist layer before firing and the individual resistors in the resistor forming openings thereof, it is possible to form a heating resistor having a uniform thickness on the inclined surface portion. That is, -i
Generally, when forming a resistive film on a sloped surface using thick film technology, it is difficult to form a resistive film with a uniform thickness because the resistor paste flows from the sloped surface.
According to the invention, a heating resistor having a uniform thickness can be easily formed on an inclined surface portion.

[Brief explanation of drawings]

Fig. 1 is an overall schematic explanatory diagram of an embodiment of the thermal head of the present invention, Fig. 2 is a perspective view of the same embodiment, Fig. 3 is an enlarged view of the part shown by the arrow ■ in Fig. 2, and Fig. 4A. is the arrow view IVA in Figure 3.
FIG. 4B is a sectional view taken along the line IVB-IVB of FIG. 4A, FIG. 4C is a sectional view taken along the C-IVC line of FIG. 4A, and FIGS. FIG. 16 is an explanatory diagram of the embodiment, and FIG. 16 is an explanatory diagram of the prior art. 2... Insulating substrate, "2c... Inclined surface portion, 3...
・Common electrode, 4...Individual electrode, 4a...Individual electrode tip, 5...Heating resistor, 5'...Individual resistor, H
O...Opening for resistor formation, RP2...Resist pattern, X...Main scanning direction Fig. 5A Fig. 7A Fig. 7B Fig. 2! Fig. 4B Fig. 6A Fig. 6B Fig. 9A Fig. 1/ Fig. 11A Fig. 8A Fig. ○A Fig. 13A Fig. 5A Fig. 12A Fig. 14A

Claims (1)

[Claims] (1) Common electrode (3) extending along the main scanning direction (X)
, a large number of individual electrodes (4) arranged in a row along the main scanning direction (X) and whose tips (4a) face the common electrode (3), and the common electrode (3). ) and a heat-generating resistor (5) connecting the individual electrode tips (4a) are formed on the surface of an insulating substrate (2). 2
c) is formed, this inclined surface portion (2c) the thermal head (2) on which the heating resistor (5) is formed, a common electrode (3) extending along the main scanning direction (X), and a common electrode (3) extending along the main scanning direction (X); A large number of individual electrodes (4) arranged in a row along the direction X) with their tips (4a) facing the common electrode (3), and the common electrode (3) and the tips of the individual electrodes. (
4a) is connected to the heating resistor (5) and the insulating substrate (2)
In the method for manufacturing a thermal head formed on the surface of the insulating substrate (2), an inclined surface portion (2c) is formed at an end of the insulating substrate (2), and then an opening for resistor formation (2c) is formed in the inclined surface portion (2c). Resist pattern (RP2) with H_0)
After that, an individual resistor (5') is formed inside the resistor forming opening (H_0), and then the individual resistor (5') is fired to form the heating resistor (5). A method for manufacturing a thermal head, the method comprising: forming a thermal head;