JPH118457A - Manufacturing method of thin film circuit board - Google Patents

Abstract

(57) Abstract: A thin film formed at a connection interface when connected to an external electrode formed on a substrate by etching to form a thin film circuit is less likely to crack or break. SOLUTION: By forming a row of concave portions 9 at connection interface positions of a mask pattern for forming external electrodes 4a and 4b by etching, the etching progresses more inward toward the concave portions 9; Electrodes 4a, 4
Even when the portion other than the portion b is removed, the inside of the concave portion 9 remains as an inclined surface. Therefore, when a thin film is formed using a plurality of inclined surfaces formed at the connection interface, there is no large step, so that the formed thin film is not constricted, and a thin film circuit without cracks or breakage caused by the thin film is formed. Can be.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a thin film circuit board for forming a thin film circuit by forming a thin film by connecting the external electrodes on a substrate having external electrodes formed by etching.

[0002]

2. Description of the Related Art FIG. 6 shows a conventional example in which an electronic component is formed on a substrate by forming a thin film circuit.
First and second external electrodes 21a, 21 for external connection
This shows a state in which the first external electrode 21a and the second external electrode 21b are connected to each other and the electronic component 22 is formed on the substrate 20 formed by etching the thin film to form the electronic component 22. The component 22 is formed as a sheet-like capacitor.

A method of forming a thin film for forming the electronic component 22 is such that a part of the first external electrode 21a is formed on the first external electrode 21a by vapor deposition or sputtering, as shown in FIG. A first internal electrode 23a is formed so as to overlap, and a dielectric material 2 is formed on the first internal electrode 23a.
4 is formed. Next, a second internal electrode 23b is formed so as to connect the dielectric material 24 and the second external electrode 21b.

[0004] By the above-described thin film forming procedure, the dielectric material 24 is sandwiched between the first internal electrode 23a and the second internal electrode 23b connecting the first external electrode 21a and the second external electrode 21b. The electronic component (capacitor) 22 can be formed.

[0005]

However, the first and second internal electrodes 23a, 2a, 2a, 2b, 2a, 2b, 2a, 2b, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2a, 2b, 2c, which are formed by forming a thin film.
3b has a thickness of about 0.1 μmt, and the first and second external electrodes 21a and 21b formed by etching have a thickness of about 10 μmt and a thickness ratio of about 1: 100.
Each external electrode 21 of each internal electrode 23a, 23b
At the connection interface with a and 21b, there is a step larger than that shown in the figure, and the thin film formation thickness on the vertical surface is small, so that constriction is apt to occur, and the defect generation rate due to cracks and breakage increases. There was a point.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a thin film circuit board capable of forming a thin film without causing a connection failure at a connection interface having a large thickness difference.

[0007]

According to a first aspect of the present invention, there is provided a thin film circuit board for forming a thin film circuit by connecting to an external electrode on a substrate on which an external electrode is formed by etching. In the manufacturing method, a mask pattern for etching an external electrode into a predetermined shape on the substrate is formed at a position serving as a connection interface with the thin-film circuit so as to have a plurality of concave portions inward from an edge. Thereafter, the thin film circuit is formed by performing an etching process and connecting to the formed external electrode.

According to the above-described manufacturing method, when an inward small area concave portion is formed at an edge of a mask pattern for forming an external electrode on a substrate by etching, and etching is performed, a large area portion is formed. There is a speed difference between the progress rate at which a small area is etched and the progress rate at which a small area is etched, and even when the corrosion of a large area is completed, the corrosion is delayed inward in the concave part as a result. Thus, an inclined surface extending from the end side toward the inside of the concave portion is formed. When a thin film is formed on an external electrode having an inclined surface formed on the edge on the thin film circuit connection side in this manner, the thin film is formed on the external electrode without forming a large step at the edge serving as a connection interface of the external electrode. Thus, a highly reliable thin film circuit can be formed without causing cracks or breaks at the connection interface.

In the recess, a plurality of recesses are arranged in a row, and the connection interface of the external electrodes is formed in a saw-tooth shape or a comb-tooth shape. In addition, the connection stability of the connection interface can be improved.

Further, by forming the shape of the concave portion with a curved line, the boundary surface between the inclined surface and the surface of the external electrode can be formed more smoothly, and the connection by forming a thin film can be stably performed.

Further, a second invention of the present application relates to a method of manufacturing a thin film circuit board for forming a thin film circuit connected to the external electrode on a substrate on which the external electrode is formed, wherein the thin film circuit of the external electrode is connected and formed. A method of forming a thin film circuit is performed after a slope forming material for forming a slope from the substrate surface to the external electrode surface is applied to the connection interface.

In the manufacturing method according to the second aspect of the present invention, the thin film is formed after the slope forming material for forming the slope at the end of the external electrode is formed on the thin film circuit connecting side of the external electrode. The step due to the thickness ratio between the external electrode and the thin film becomes gentle on the inclined surface, and the thin film formed on the inclined surface is less likely to crack or break, and a highly reliable thin film circuit can be formed.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention.

FIG. 1A is a plan view showing a state in which a capacitor is formed on a substrate 5 by the method for manufacturing a thin film circuit board according to the first embodiment of the present invention. As shown in the figure, a first internal electrode 3a and a second internal electrode 3b are formed between a first external electrode 4a and a second external electrode 4b formed on a substrate 5 by etching or the like.
By forming the dielectric material 6, the capacitor 1 is formed between the first external electrode 4a and the second external electrode 4b.

FIG. 1B is a cross-sectional view taken along line AA of FIG. 1A, and shows first and second external electrodes 4a, 4a.
b Since the connection interface with each of the first and second internal electrodes 3a and 3b is formed on an inclined surface, the connection interface is formed when the first and second internal electrodes 3a and 3b are formed as a thin film. Since constriction does not occur, a crack or breakage due to the constriction does not occur, and a highly reliable connection structure can be formed.

A method for forming an inclined surface at the connection interface between the first and second external electrodes 4a and 4b will be described with reference to FIGS.

The first and second external electrodes 4a and 4b are formed by a substrate material on which a material film (copper foil or the like) for forming the first and second external electrodes 4a and 4b is adhered. 8 is formed by etching. As shown in FIG. 2A, each of the mask patterns 7a and 7b for forming the first and second external electrodes 4a and 4b is formed with the first and second internal electrodes 3a and 3b. It is applied in a pattern in which a plurality of concave portions 9 are provided in a sawtooth shape on the connection interface side. When the substrate material 8 provided with such mask patterns 7a and 7b is subjected to etching, the etching proceeds at a small area of the concave portion 9 at a low speed. Also, the etching is delayed more toward the inner side of the concave portion 9, and as a result, as shown in FIG.
As shown in (b), the surface that has not been completely etched in the recess 9 remains as an inclined surface corresponding to the etching rate. Therefore, when the portions other than the portions left as the first and second external electrodes 4a and 4b are removed by etching from the substrate material 8 by etching, the inclined surfaces are respectively formed at the positions of the plurality of concave portions 9 formed at the end sides on the connection interface side. Are formed, and the first and second external electrodes 4a, 4a and 4b are formed on the connection interface side with a plurality of inclined surfaces as shown in the cross-sectional view of FIG.
b is formed on the substrate 5.

As described above, the first and second external electrodes 4a,
As shown in FIG. 1B, the first and second internal electrodes 3a and 3b are connected to the first and second external electrodes 4a and 4b on the substrate 5 on which the 4b is formed. When formed, the connection interface with each of the external electrodes 4a and 4b is connected by an inclined surface, so that there is no large step due to the thickness ratio, so that the formed thin film does not become constricted, and a thin film without cracks or breakage is formed. be able to.

The recesses 9 are formed by the mask patterns 7a and 7b by masking and etching using comb-shaped mask patterns 7c and 7d in which rectangular recesses 9a are arranged in a row as shown in FIG. Also in this case, since the etching proceeds at a lower rate toward the inner side of the concave portion 9a, an inclined surface is formed in the concave portion 9a, and a plurality of the inclined surfaces are used as connection interfaces. be able to. Further, as shown in FIGS. 4A and 4B, a mask pattern 7 in which the corners of the concave portions 9b and 9c are formed in a curved line.
By performing etching using e and 7f, the corners and inclined surfaces of the connection interface can be formed smoothly, and the connection interface can be formed in a shape with less corners.
The connection with 3b can be further stabilized.

Next, a method of manufacturing a thin film circuit according to a second embodiment of the present invention will be described.

FIG. 5 is a cross-sectional view showing a state in which the capacitor 2 is formed on the substrate 15 by the method of manufacturing a thin film circuit board according to the present embodiment.

The procedure for manufacturing the capacitor 2 by forming a thin film is as follows. First, the external electrodes 10a, 10b are formed on the substrate 15 on which the first and second external electrodes 10a, 10b are formed.
By applying the inclined surface forming materials 11a and 11b made of a resin such as polyimide to the respective connection interface positions, the inclined surfaces are formed by the surface tension as shown in the figure.

Next, the first internal electrode 12a extends from the first external electrode 10a to the inclined surface forming material 11a and the substrate 15.
Is formed by a thin film forming means such as sputtering or vapor deposition. A dielectric material 13 is formed in a thin film at a position on the substrate 15 of the internal electrode 12a.
5. A thin film of the second internal electrode 12b is formed on the surface up to the inclined surface forming material 11b and the second external electrode 10b. By forming this thin film, the first internal electrode 12a and the second internal electrode 1
The capacitor 2 is formed with the dielectric material 13 interposed therebetween and the internal electrodes 12a and 12b are connected to the external electrodes 10a and 10b, respectively, whereby the capacitor 2 is formed on the substrate 15 by forming a thin film. can do.

According to the above configuration, the first and second internal electrodes 12a and 12b and the first and second external electrodes 10a and
10b is connected to each inclined surface forming material 11
Since the inclined surfaces are formed by a and 11b, a sharp step due to the thickness ratio is eliminated, and the formation of the thin film is less likely to be clogged.

In each of the embodiments described above, a method of forming a capacitor circuit on a substrate by forming a thin film has been described. However, a thin film circuit is formed on a substrate on which external electrodes for external connection are formed by soldering. In such a case, a thin film circuit board can be manufactured using the same method.

[0026]

As described above, according to the first aspect of the present invention, since the inclined surface is formed at the connection interface of the thin film circuit of the external electrode formed on the substrate, the inclined surface is formed at the connection interface of the external electrode. Since a thin film circuit can be formed by connecting to an external electrode without forming a large step, a highly reliable thin film circuit can be formed without causing a crack or break in a formed thin film.

According to the second aspect of the present invention, the thin film is formed after the inclined surface is formed by the inclined surface forming material on the connection interface of the thin film circuit connection of the external electrode formed on the substrate. Due to the material, the step due to the thickness ratio between the external electrode and the thin film becomes gentle on the inclined surface, the thin film formed on the inclined surface is less likely to crack or break, and a highly reliable thin film circuit can be formed .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example (a) of a thin-film circuit manufactured by a manufacturing method according to a first embodiment of the present invention and a thin-film formation state (b) of a cross section taken along line AA of FIG.

2A and 2B are a perspective view and a cross-sectional view illustrating an example of a mask pattern (a) for etching an external electrode and a concave shape (b) after the etching process.

FIG. 3 is a plan view showing another mask pattern (a) forming an inclined surface at a connection interface, and a perspective view showing a formed concave shape (b).

FIG. 4 is a plan view showing another mask pattern example (a) and (b) for forming an inclined surface at a connection interface.

FIG. 5 is a sectional view showing a state of forming a thin film circuit manufactured by a manufacturing method according to a second embodiment of the present invention.

6A is a plan view showing a thin film circuit formed by a conventional manufacturing method, and FIG. 6B is a cross-sectional view showing a cross section thereof.

[Explanation of symbols]

 1, 2 Capacitor (thin film circuit) 3a, 3b, 12a, 12b Internal electrode 4a, 4b, 10a, 10b External electrode 5, 15 Substrate 7a, 7b, 7c, 7d, 7e, 7f Mask pattern 9, 9a, 9b, 9c Recesses 11a, 11b Inclined surface forming material

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuo Arisue 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. A method of manufacturing a thin-film circuit board, wherein a thin-film circuit is formed by connecting to an external electrode on a substrate on which an external electrode is formed by etching, wherein a mask for etching the external electrode into a predetermined shape on the substrate is provided. A pattern is formed at a position serving as a connection interface with the thin film circuit so as to have a plurality of concave portions directed inward from an edge, and then subjected to an etching process and connected to the formed external electrodes to form a thin film circuit. A method for manufacturing a thin film circuit board, comprising: 2. The connection interface between external electrodes is formed in a saw-tooth shape or a comb-tooth shape by arranging a plurality of recesses.
A method for manufacturing the thin film circuit board according to the above. 3. The method for manufacturing a thin film circuit board according to claim 1, wherein the shape of the concave portion is formed by a curve. 4. A method for manufacturing a thin-film circuit board, wherein a thin-film circuit connected to the external electrode is formed on a substrate on which an external electrode is formed.
A method for manufacturing a thin film circuit board, comprising: forming a thin film circuit after applying a slope forming material for forming a slope from a substrate surface to an external electrode surface.