JPS6248094A - Film formation for conductor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forming a conductor film, which is applied when forming electrodes on an insulating substrate, for example, in a thermal head.

[Prior Art] For example, in forming the electrodes of a thermal head, a conductor film is first formed on an insulating substrate such as a ceramic substrate, and conventionally, this conductor film has been formed by a thick film method. That is, as shown in FIG. 3, a conductive paste (2) containing a conductive material such as gold is placed on a screen (4), and a squeegee (5) is used to squeegee the conductive paste (2).
) on the screen (4), and
The conductive paste (2) is printed on the insulating substrate (1) set under the conductive paste (2), and then the conductive paste (2)
A conductive film is formed by firing. Then, the conductor film is subjected to pattern defects using well-known etching techniques or the like to form electrodes.

[Problems to be Solved by the Invention] However, the conventional method for forming a conductor film as described above has the drawback that the conductor film can only be formed on one side of the insulating substrate (1). Foreign matter or dust attached to the screen (4) may be removed from the insulating substrate (1).
There is a problem in that it is printed together with the conductive paste (2), causing pattern defects.

Here, the fact that the conductive film can only be formed on one side of the insulating substrate (1) causes the following problems in the case of a thermal head.

FIG. 5 shows a perspective view of a thermal head using a conventional conductor film forming method. Here, (1) is an insulating substrate, (8) is a common electrode formed by firing a conductive paste, (7) is an integrated circuit formed on the insulating substrate (1), (8) is the output lead of the integrated circuit (7),
(9) is a control lead of the integrated circuit (7), and (10) is a heating resistor. The common electrode (13) has a comb tooth portion (6a).
are formed, and the tips of the output leads (8) are inserted alternately between the southern parts of the comb (8a). and,
The heat generating resistor (1
control lead (8) of the integrated circuit (7) in which the control lead (8) is formed
), an output pulse appears on a given one of the output leads (8) of the integrated circuit (7), and due to the potential difference created between the output lead (8) and the common pole (6), The heating resistor (10) is partially energized and generates heat,
Printing is performed on thermal recording paper (not shown) set on the upper surface of the heating resistor (10).

In such a thermal head, the common electrode (6)
Since the printed side is the printed surface, it is necessary to bring out the common lead (6b) of the common electrode (G) to the same side as the control lead (9) of the integrated circuit (7). Since the film is deposited on only one side of the common lead (6b), the common lead (6b) must be drawn out from the side end on the same plane as the control lead (9), as shown.

Therefore, the area on the insulating substrate (1) increases by this common lead (6b), and from the viewpoint of current capacity, the area occupied not only by the common lead (6b) but also by the common electrode (6) itself. Since it is necessary to make the thermal head considerably large, there is a problem that the surface area of the insulating substrate (1) increases and the overall shape of the thermal head becomes large.

In addition, since the common lead (6b) is located at the end of the insulating substrate (1) h, the distance from the common lead (6b) to each comb tooth part (6a), that is, the resistance value, is different. Therefore, the amount of heat generated varies in each part of the heating resistor (10), resulting in non-uniform printing.

This invention was made in order to eliminate the above-mentioned conventional problems, and it is possible to form a conductive film on both sides of an insulating substrate, and even when applied to the manufacture of thermal heads, the head does not become large. To provide a method for forming a film of a conductor, which is capable of uniform printing, and which does not cause defects such as foreign matter or dust attached to a screen being printed on an insulating substrate and causing pattern defects.

[Means for Solving the Problems] A method for forming a conductor film according to the present invention includes forming paste layers on both sides of the insulating substrate by immersing the insulating substrate in a conductive paste filled in a container. The method is characterized in that the insulating substrate is then pulled up and the paste layer is fired.

[Production] In the present invention, a paste layer is formed by dipping an insulating substrate in a conductive paste, so a conductive film can be easily formed on both sides of the insulating substrate. Unlike the conventional thick film method, the method of this invention does not use screen printing, so foreign matter and dust attached to the screen are printed on the insulating substrate together with the conductive paste, forming a pattern. No defects occur.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a process diagram showing an embodiment of the method for forming a conductor film according to the present invention. As shown in Figure (a), the container (3)
conductive paste containing conductive material such as gold) (2),
For example, it is filled with an organic gold paste (Metal Organic Paste A-4615 manufactured by Engelhardt), and an insulating substrate (1) made of ceramic or the like is completely immersed in this conductive paste (2). After that, the insulating substrate (1
) is pulled up from the conductive paste (2) and fired, the entire surface of the insulating substrate (+) is covered with a paste layer (20), as shown in FIG. 3(b).

FIG. 2 is a process diagram showing another embodiment of the method for forming a conductor film according to the present invention. In this embodiment, first, as shown in FIG. 2(a), an insulating substrate (1) is held horizontally and the entire surface of one side is immersed in a conductive paste (2). Next, as shown in FIG. 4B, the insulating substrate (1) is held vertically and partially immersed in the conductive paste (2). Then apply the insulating substrate (1) to the conductive paste (2).
When the paste layer (20) is coated on one side and the entire side surface of the insulating substrate (1) and a portion of the other side, as shown in FIG. It will be done.

FIG. 4 shows a perspective view of a thermal head using the conductor film forming method according to the embodiment shown in FIG. Here, (1
) is an insulating substrate, (6) is a common electrode formed from conductive paste (2), (7) is an integrated circuit formed on the insulating substrate (1), and (8) is an integrated circuit (7). (9) is a control lead of the integrated circuit (7), and (10) is a heating resistor. The common electrode (6) has a comb tooth portion (6a).
are formed, and the tips of the output leads (8) are inserted alternately between the comb teeth (6a). and,
The heat generating resistor (1
0) is formed.

This thermal head differs from the one in FIG. 5 in that the common electrode (6) is formed not only on a part of the front surface of the insulating substrate (1) but also on the entire side and back surface. According to such a structure, the common lead (6b) of the common electrode (6)
) can be pulled out from the back side of the insulating substrate (1), and there is no need to pull it out from the side end on the same plane as the control lead (9) as in the conventional case.

Furthermore, since the common electrode (6) is also formed on the side and back surfaces of the insulating substrate (1), the area of the common electrode (6) on the surface of the insulating substrate (1) can be reduced.
The shape of the thermal head is reduced in size.

Furthermore, since the common lead (6b) is formed over the entire back surface of the insulating substrate (1), the common lead (6b) is formed over the entire back surface of the insulating substrate (1).
The resistance value from b) to the southern part (6a) becomes uniform, and the non-uniformity of printing due to variations in the amount of heat generated in each part of the heating resistor (10) is improved.

Furthermore, by grounding the common lead (6b), a shielding effect of the integrated circuit (7) can be achieved, and malfunction of the integrated circuit (7) due to external surge signals can be prevented.

In addition, in any of the above embodiments, since screen printing is not used, there is no risk that foreign matter, dust, etc. from the screen will adhere to the insulating substrate (1) and cause defects in the pattern.

[Effects of the Invention] As described above, according to the present invention, a paste layer can be easily formed on both sides of an insulating substrate by dipping the insulating substrate in a conductive paste. It is suitable for manufacturing (1), and even in this case, the head does not become large, and moreover, uniform printing is possible.

Furthermore, it is possible to prevent problems such as defects in patterns caused by foreign matter or dust attached to the screen.

[Brief explanation of the drawing]

FIG. 1 is a process diagram showing one embodiment of the conductor film forming method according to the present invention, FIG. 2 is a process diagram showing another embodiment of the conductor film forming method according to the present invention, and FIG. 3 is a process diagram showing a conventional screen forming method. A perspective view showing a method of forming a conductor film by printing, FIG. 4 is a perspective view of a thermal head obtained by the method of forming a conductor film of the present invention, and FIG. 5 shows a thermal head obtained by a conventional method of forming a conductor film. FIG. 3 is a perspective view of the head. (1)... Insulating substrate, (2)... Conductive paste, (3)... Container, (20)... Paste layer. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) A paste layer is formed on both sides of the insulating substrate by immersing the insulating substrate in a conductive paste filled in a container, and then the insulating substrate is pulled up and the paste layer is fired. Characteristic conductor film formation method. (2) Hold the insulating substrate horizontally and first immerse the entire surface of one side in the conductive paste, then hold the insulating substrate vertically and partially immerse the other side in the conductive paste. A method for forming a film of a conductor according to claim 1.