JPS6019553A - Method and apparatus for manufacturing thermal head - Google Patents

Abstract

PURPOSE:To achieve a higher productivity by arranging electrically insulating substrates comprising resistance thin films in one row on a holder with a clearance therebetween to form an electrode film on the four surfaces of the substrate by sputtering the same materials simultaneously from both sides. CONSTITUTION:A substrate 43 is normally made up of a chromium-copper double layer film formed on an electrically insulating substrate. In the form of the film, the substrates 43 are arranged in a row on a holder 42 with a clearance therebetween and a sputtering is performed simultaneously with opposed targets 41 comprising the same material on them being moved with a holder moving mechanism 45 to form a film on the four surfaces thereof. Thus, as the film formation is done with moving the holder 42 holding the heat generating body substrates 43 continuously, the productivity remains the same as that in the making of electrode films of the conventional flat type head and the formation of even films is made possible on the four surfaces thereby elevating the productivity and reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The thermosensitive recording method has the advantage of being easy to maintain, and is used in many terminal links including facsimile machines. In recent years, thermal transfer methods have been developed, making it possible to record in multiple colors and in full color, and new recording equipment is about to be developed.

The present invention relates to a thermal head used for thermal recording, and more specifically to a method and apparatus for forming an electrode film of an edge-type thermal head that is optimal for use as a color recording head.

Conventional configuration and its problems Printing speed of thermal head 1) In order to increase ffit, a head has been developed in which a drive IC including a shift register and a latch is integrated, and a head is mounted integrally on the entire heating element board. ing. This head is shown in FIG.

The head shown in FIG. 1 has a head structure in which a driving IC is fixed on a heat generating substrate and mounted by wire bonding.

In Figure 1, 1 is an alumina substrate with glass glaze on the entire surface, 1a is a heating element, 1b is a common electrode, 1C is an individual electric current, 2 is a common electrode lead, 2a is a common electrode lead and a common electrode. 3 is the drive IC, 6 is the base, 7 is the cover for crimping the film lead 10 and the reservoir, 8 is the rubber for crimping, 9 is the cover fixing hole, 10 is the film lead , 11 is a spacer for fixing the film lead, 12 is a spacer for crimping the common electrode lead, and 13 is a wire for wire bonding. Note that a wear-resistant protective film is provided on the heating element portion, but it is not shown. The head shown in FIG. 1 may be mounted using a wire bonding method, or there may be another mounting method using a film carrier. All of these heads have electrode wiring only on the blood that forms the heating element, so below they are referred to as flat heads.○In such flat heads, the electrode film is one
Since it is sufficient to form the film on only one plane, it is possible to use a normal film forming apparatus.

However, the flat head has major problems, especially when color recording is performed using a thermal transfer method. FIG. 2 shows the configuration of a recording section to prevent color misregistration, which is an important problem in the thermal transfer method. In FIG. 22 is transfer paper, and on this paper are fan 22a, magenta 22b, yellow o 22
Each color of C+black 22d is applied in sequence with a length approximately equal to the length of one revolution of the roller 21. Note that the order of this color changes depending on the device and ink.
Color recording is performed by sequentially printing each color onto receiver paper. As can be seen from the figure, in a recording apparatus having this structure, it is desirable in device design that the heating element forming surface of the thermal head be as small as possible. The conventional flat head is unsuitable for use as a color recording head using a thermal transfer method.As a head suitable for such color recording, the head shown in FIG. 3 invented by the present inventors is shown in FIG. be.

Since the head shown in FIG. 3 has a head structure in which the heating element is entirely formed on the end face of the substrate, it is hereinafter referred to as an end face type head.

In FIG. 3, 3o is an alumina substrate, 31 is a common electrode, 32 is an individual electrode, and 33 is a glass layer, which is formed continuously and smoothly at the end surface. 34 is a drive 1C135 is a base, 36 is a cover for crimping and holding the film lead 37, 39 is a rubber for crimping, 40 is a cover fixing device), 37 is a film lead, and a cover for the drive IC. Pressure contact with external connection electrode and common electrode. 41 is a wire for wire bonding.

Although a row of heating elements is provided on the end face 42, no heating element is provided on the end face due to the shape of the figure. It is clear that such an end face type head is very useful as a color recording head as described above.

However, the head of this method has important problems in manufacturing. First, to form a continuous fine pattern without any disconnections from the end face to the main plane, and second, to form a uniform electrode film on four sides, two end faces and two main planes. It is.

In particular, regarding the second problem, there has been no method or apparatus for forming electrode films on four sides of a large-area substrate such as a thermal head with good productivity and reliability.

OBJECTS OF THE INVENTION The present invention provides a method and apparatus for forming an electrode pattern of an edge-type thermal head with good reliability and productivity, which is particularly useful in color recording using a thermal transfer method.

Structure of the Invention In the method for manufacturing a thermal head of the present invention, electrically insulating substrates on which a resistive thin film is formed are arranged in a line in a holder with a gap that is approximately the same as the width of the substrate, and By simultaneously sputtering the same material from both sides of the substrate, electrode films can be formed on the four sides of the substrate. ζ
Furthermore, the manufacturing apparatus of the present invention includes flat cugets made of the same material disposed at opposing positions in the sputtering vacuum chamber, and a holder that removably supports the substrates in a line with a gap between them. The apparatus is equipped with a mechanism for linearly moving the holder at a position in the middle of the Kuke'Hf3J, and a mechanism for discharging the holder at the same time as the front target is aligned with the opposing target.

Description of Embodiments 1 First, the length of the substrate of the thermal head is almost determined by the printing 11IF;S, and the most commonly used size is A4 or B4. Furthermore, as mentioned above, it is necessary to integrally mount the driving IC, so the width needs to be about 40 mm. edge 1n1
Although the required width of the board can be reduced with type thermal head, the length remains the same.From these points, the board for thermal head is very thick even if it is Hanwa surface type. In particular, there was no apparatus that could produce a uniform film on all four sides with good productivity.

Incidentally, as the electrode film of the thermal head, it is required to use copper or aluminum from the viewpoint of material cost. %, copper is excellent in that it can be plated, and in many cases, electrolytic membranes mainly made of copper are used. Copper has poor adhesion to the base plate, so chromium is used as the base.2
A layered method is used. The adhesion of chromium and copper in this chromium-copper two-layer film was examined in particular. Regarding voltage detection items, the influence of film formation speed in intermittent film formation process and continuous film formation process was investigated. As shown in the adhesion table for the 0 film formation process shown in Table 1 below, the results show that when a film is formed only on the - side, adhesion can be ensured within a sufficient range. On the other hand, in an intermittent formation method in which the substrate is rotated to form a film on four substrates, it is necessary to increase the film formation rate. There is no apparatus that can form a film while rotating a large number of substrates of a thermal head and at the same time ensuring a film formation speed as described in the above.

From these experimental results, in order to perform reliable film formation on four sides, it is important to be able to continuously form a film on four sides at the same time.

In spackling, the film is formed in a low-pressure gas, which results in good spooling.In addition, the magnetron method speeds up metal film formation very quickly.From these points, the present invention has the advantage that the film is formed in the same phase at opposing positions. '', the heating element substrate is supported on a holder with an interval approximately the same as the width of the substrate, and the holder is moved linearly at a position midway between all of the opposing targets. i) This is a method in which electrode films are formed on four layers by sputtering at the same time.

FIG. 4 shows an example target of an embodiment of the present invention.

Indicates the state of board arrangement. The diagram shown in FIG. 4 is a diagram schematically explaining the arrangement of the substrate and the position of the holder.

41 is a target made of the same material placed in opposing positions, 42 is a holder, 43 is a substrate for an end face type thermal head, 44 is a holder support, and 46 is a holder moving mechanism. .

By rearranging the substrates 43 with a gap and simultaneously sputtering them with the opposing targets 41 while moving in the direction of the arrow, films can be formed on all four surfaces with high productivity.

FIG. 5 shows a production apparatus having the configuration shown in FIG. 4.

In FIG. 5, 51 is a target for a lower layer film, 42 is a holder, 43 is a heating element substrate, 56 is a target for an upper layer film,
57 is a holding stocker, 58 is a holder stocker after film formation, 59 is an oil diffusion pump, and 60 is a rotary pump.

This apparatus forms a film while continuously moving the holder that holds the heat generating substrate 43. For this reason, the production capacity is no different from the production of electrode films for conventional planar heads. However, since sputtering is performed simultaneously from both opposing sides, a large amount of electric power is required for discharging, but since a metal film is being created and direct current sputtering is possible, the cost of the device is hardly affected.

Furthermore, as shown in FIG.
By making 56 a simple flat plate with both sides protruding, it is possible to form a film more uniformly on the four surfaces. In FIG. 6, the same numbers as in FIG. 5 indicate the same names.

The target shown in FIG. 6 may be prepared in advance in the shape shown in the figure, but the light intensity pJ can also be obtained by arranging a flat target obliquely, and there is no problem with the second method.

Effects of the Invention According to the present invention, it is possible to form electrode films on four sides required for an end-face type head with high productivity and reliability, and this invention greatly contributes to the popularization of color recording devices.

4. f in the drawing? i'j llJ, な congratulations Figure 1 is a partially cut away perspective view 9J showing the structure of a conventional planar thermal head.
Fig. 2 is a schematic diagram when color recording is performed using a thermal transfer method, Fig. 3 is a partially cutaway perspective view showing the structure of an edge type thermal head, and Fig. 4 is a film forming apparatus in an embodiment of the present invention. A schematic diagram showing the arrangement of the substrate, movement of the holder, and arrangement of the cuget, FIG. 5 is a schematic diagram showing an embodiment of the film forming apparatus of the present invention, and FIG. FIG. 1 is a schematic diagram showing an embodiment of a film forming apparatus having a terkelat shape for forming a film.

41.51.56...Target, 42...
Holder, 43... Substrate for Tsutsumen type thermal head, 4
5...Holder moving mechanism.

Claims (2)

[Claims] (1) The electrically insulating substrates on which the resistive thin film is formed are arranged in a row on a holder with gaps, and the same material is sputtered simultaneously from both sides of the holder to replace the electrodes on the four sides of the substrate. A method of manufacturing a thermal head, comprising: forming a thermal head. (2) Planar targets made of the same material placed at opposing positions in the vacuum chamber for Suhanota, a holder that removably supports the substrate in a line with a gap, and a holder that supports the substrate between the targets. 1. A thermal head manufacturing apparatus comprising: a mechanism that moves linearly at an intermediate position; and a mechanism that simultaneously discharges the same target.