JPH0390366A - Manufacture of thermal head array - Google Patents

Abstract

PURPOSE:To prevent the quality of recorded data from deteriorating and to make the whole thermal head array compact by forming the array on an enamelled substrate and using the electroconductive core of the enamelled substrate as a common electrode. CONSTITUTION:A thermal resistor 1, a power supply side wiring pattern 7, and a grounding side wiring pattern 8 are formed on an enamelled substrate 18, and an anti-oxidation layer 16 and an abrasion-resistant layer 17 are formed on the surface of these components. Then the enamelled substrate 18 is cut along a dot and dash line Y-Y, and the ends of the cut parts are discarded as unnecessary parts. Next an electrically conductive layer is formed on the cross-sections of the cut parts using electrolytic plating technique, or an electroconductive paste 14 is applied onto the cross-sections and then the applied paste is baked. Another method is to evaporate or sputter an electroconductive substance and connect each lead conductor of the power supply side wiring pattern 7 to an electroconductive core 11. After this, to protect a part where the power supply side wiring pattern 7 and the electroconductive core 11 are connected together, an insulating film 15 is formed on the applied electroconductive paste 14.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a thermal head array used in a thermal recording device.

[Prior Art] First, the operation of a thermal head array manufactured according to the present invention will be explained. Figure 3 is a connection diagram showing the operation of the thermal head array. In the figure, (1) is the heating resistor of the thermal head array, (2) is the shift register,
(3) is the latch, (4) is the driver, (5> is the DC power supply, (6) is the common electrode, (7> is the power supply side wiring pattern, (
8) is the ground side wiring pattern.

Note that the shift register (2) includes an external circuit (not shown).
The data signal and clock signal are input from the latch (
A latch signal that controls the timing of writing data from the shift register (2) is input to the driver (4).
According to the logic of the corresponding latch (3), the driver (
4) is input with a strobe signal that controls the operating time.

Shift register (2), latch (3), driver (4)
The operation controls which lead conductor is grounded among the plurality of lead conductors of the ground side wiring pattern (8), but these shift registers (2), latches (3), and drivers (4) are normally Since it is composed of an IC, it is collectively referred to as a control circuit IC (10).For example, a lead conductor (8a) of the ground side wiring pattern (8> Then, current flows through (7a), (8a), and (7b)-(8a), and the portion (la) of the heating resistor (1) generates heat.

FIG. 4 is a plan view schematically showing a conventional thermal head array, in which the same reference numerals as in FIG. 3 indicate the same or corresponding parts.

If there is a voltage drop at the common electrode (6), the magnitude of the current flowing through the heating resistor (1) will differ, and the density of the recorded result will be uneven depending on the position of the thermal head in the thermal array. This results in a decrease in quality. Therefore, in order to prevent a voltage drop, the common electrode (6) is made wider or thicker so that the resistance is as small as possible.

Further, depending on the case, the common electrode (6) may be created using a braided wire or a bus bar, or a conductive treatment may be applied to the back surface of the substrate to form a part of the common electrode (6>).

By the way, in a thermal head array called an etch type, the heating resistor (1) is formed as close to the edge of the substrate as possible. This means that the records recorded on the recording paper by the heating resistor (1) are fed from below the substrate on which the thermal head array is formed, so that the records can be seen by the observer as quickly as possible. This is to ensure that.

[Problems to be Solved by the Invention] The conventional manufacturing method of the thermal head array as described above is as explained above, but in the conventional manufacturing method, it is difficult to sufficiently reduce the resistance of the common electrode (6) due to the This is particularly difficult for etch-type thermal head arrays. In other words, as is clear from Fig. 4, when the width of the common electrode layer 6) is increased, the heating resistor (
1> away from the edge of the board. In addition, when increasing the thickness of the common electrode (6), in order to prevent the common electrode (6) from hitting the platen when the heating resistor (1) is pressed against the recording paper on the platen, the heating resistor (6) must be made thicker. body (1)
This is because the common electrode must be kept away from the pole (6), and as a result, the heating resistor (1) is kept away from the edge of the substrate.

In addition, in conventional manufacturing methods, as the total length of the thermal head array becomes longer, the resistance of the common electrode (6) must become smaller and smaller in order to supply the same voltage to every lead conductor of the power supply side wiring pattern (7). , and the common electrode (6) had to have a special shape.

This invention was made to solve this problem, and by using a common electrode that occupies a sufficiently small area on the substrate surface and has a sufficiently low resistance, the entire structure can be made compact without deteriorating the recording quality. The object of the present invention is to provide a method for manufacturing a thermal head array that allows the recording results to be observed almost simultaneously.

[Means for Solving the Problems] A method for manufacturing a thermal head array according to the present invention includes:
Enamel the thermal head array.

This is formed on a substrate (hereinafter referred to as enamel), and the conductive core of the enamel substrate is used as a common electrode.

[The electrical resistance of the conductive core of the working substrate is sufficiently small;
Further, it can be easily realized by connecting the power supply side wiring pattern to the conductive core of the enamel substrate, cutting the enamel substrate, and applying a conductive paste to the cut surface.

[Examples] Examples of the present invention will be described below with reference to the drawings. 1st
The figure is a sectional view showing one embodiment of the present invention, and FIG. 2 is a schematic plan view thereof. In each figure, the same reference numerals as in FIG. 3 indicate the same or corresponding parts, and (11) is the enamel substrate. Conductive core, (12) is the glass material forming the enamel of the enamel substrate, (13) is the glass material formed on the surface of the enamel substrate, (14) is the conductive paste, (15> is the insulating film, ( 16) is an antioxidation layer, (17) is an abrasion resistant layer, and (18) is a conductive core (11) and a glassy material (1).
2) shows an enamel substrate formed by and.

In the manufacturing method according to the present invention, in the first step, a heating resistor (1) is placed on an enamel substrate (18).

Power side wiring pattern (7), ground side wiring pattern (8)
When the control circuit IC (10) shown in FIG. 2 is not installed, an anti-oxidation layer (16) and an anti-wear layer (17) are formed on the surface thereof. When this first step is completed, the cross section taken along the dashed line AA shown in FIG. 2 becomes as shown in FIG. 1(a).

In the next step, the enamel substrate 18) is placed along the dashed-dotted line Y-Y in the cross-sectional view shown in FIG. 1, and along the dashed-dotted line XX in the plan view shown in FIG. cut,
Discard the cut ends as unnecessary parts. The cross section after this cutting step is shown in FIG. 1(b).

In the next step, a conductive layer is formed on the cut surface by electrolytic plating or a conductive paste (14)
is applied and fired, or a conductive substance is deposited or sputtered, and then each lead conductor of the power supply side wiring pattern (7) is connected to the conductive core (11>).

In this case, including the cutting line X-X, a wiring pattern (
By forming 〉 (not shown), the power supply side wiring pattern (7〉) can be more reliably connected to the conductive core (11).

Then, the power supply side wiring pattern (7) and the conductive core (ll)
To protect the connection part with the conductive paste (
An insulating film (15) is formed on the film (14) and the like.

To connect a power source to the conductive core (11), part of the glass (12) of the enamel substrate (18) is peeled off, anti-rust treatment is applied, and connection electrodes (not shown) are provided. Connect the electrode to the electrode for use.

Then, the control circuit IC (10) is mounted on the enamel substrate (18) on which the above steps have been completed.

The thermal head manufactured in this way has a sufficiently low electrical resistance of the conductive core (11), so the same voltage can be applied to any lead conductor of the power supply side wiring pattern (7), making it possible to record heat-sensitive data. can improve the quality of

In addition, since the cut @ It is possible to configure the system so that the results can be observed almost simultaneously with recording.

Furthermore, since the various special structures required to construct the common electrode in conventional thermal heads are no longer required, the overall structure can be made more compact.

[Effects of the Invention] As explained above, this invention makes it possible to sufficiently reduce the electrical resistance of the common electrode and to sufficiently shorten the distance from the array line of the heating resistors to the edge of the substrate, thereby improving the recording quality. The present invention has the advantage that it is possible to manufacture a thermal head array that can be made compact as a whole without reducing the performance, and can observe the recording results almost at the same time as recording.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a schematic plan view showing an embodiment of the invention, FIG. 3 is a connection diagram explaining the operation of the thermal head array, and FIG. 4 is a plan view schematically showing a conventional thermal head array. (1> is the heating resistor, (7) is the power supply side wiring pattern, 8) is the ground side wiring pattern, 10) is the control circuit IC1
(11) is a conductive core, (12) is glassy, (14)
(15) is a conductive paste, (15) is an insulating film, (16) is an anti-oxidation layer, (17) is a wear-resistant layer, and (18) is an enamel substrate. Note that the same reference numerals in each figure indicate the same or corresponding parts. 17: Wear-resistant layer diagram; Enamel substrate diagram

Claims (1)

[Claims] A thermal head array is provided in which a plurality of thermal heads, which are heating elements, are arranged in contact with a thermal recording paper and in a direction perpendicular to the direction of relative movement between the thermal head array and the thermal recording paper. A method for manufacturing a thermal head array includes a step of forming heating resistors in a straight line on an enamel substrate having a conductive core, and arranging them at approximately equal intervals in a direction perpendicular to the straight line of the heating resistors. A plurality of lead conductors are formed each contacting and crossing the heating resistor, and every other lead conductor is divided into a power supply side wiring pattern and a grounding side wiring pattern, and a power supply side wiring pattern is formed. and a ground-side wiring pattern are formed by extending in directions opposite to each other with respect to the heat-generating resistor, and a process of forming an oxidation prevention layer on the heat-generating resistor, the power-side wiring pattern, and the ground-side wiring pattern. , forming a wear-resistant layer on the anti-oxidation layer, on the side where the power supply side wiring pattern is formed, the enamel substrate is moved in a straight line parallel to the straight line of the heating resistor at a position close to the heating resistor; A step of electrically connecting the power supply side wiring pattern remaining after being cut in this cutting step to the conductive core of the enamel substrate through the cut surface, a step of cutting the power supply side wiring pattern along the A method for manufacturing a thermal head array, comprising the step of forming an insulating film on a cut surface that is electrically connected to the conductive core of the enamel substrate.