JPS6020918B2 - Method of forming thick film conductor pattern - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of patterning thick film conductors in a hybrid integrated circuit board.

Conventionally, methods for forming thick film conductor patterns include a method of printing and firing using a screen onto which a desired pattern has been transferred, and a method of printing and firing a thick film conductor on the entire surface of a substrate and patterning it by photoetching. I've been exposed to it.

However, in the former method, it is difficult to form a fine pattern, and the practical minimum pattern width is 1.
It is about 00 French meters.

On the other hand, in the latter method, although it is possible to form fine patterns, a lot of material is wasted because conductors are printed and fired on the entire surface of the substrate and then unnecessary portions of the conductors are removed.

Furthermore, in multilayer wiring boards, etc., the lower layer conductor pattern is
If the conductor is exposed from the insulating layer, the lower conductor is also etched when the upper conductor is photoetched, making it impossible to form such a pattern. In the present invention, in order to eliminate the above-mentioned drawbacks, a thick film conductor is formed by screen printing in an area containing a desired pattern, and then only a fine pattern area where it is impossible to form a pattern by screen printing is patterned by photoetching. It is something that forms.

Therefore, it is an object of the present invention to provide a method for forming a thick conductor pattern that reduces waste of conductor material and enables the formation of fine patterns that are impossible with screen printing. The present invention will be described in detail below based on Examples and with reference to the drawings.

FIGS. 1A to 1C are plan views showing one embodiment of the present invention, and FIGS. 1A to 1C are sectional views taken along line A-A' in each of the plan views.

Using a screen onto which a desired pattern has been transferred, thick film conductors 2 and 2' are printed and fired on an insulating substrate 1 (see Fig. 1A,
stomach').

The pattern 2 that can be formed by screen printing has a desired shape, and the fine pattern that cannot be formed by screen printing has a size that can be printed by screen.
A thick film conductor 2' is printed and fired in a region containing a desired fine pattern. Next, photoresists 3 and 3' are formed on the substrate for the purpose of forming a fine pattern (see FIG.
).

The photoresist 3' is used to form a fine pattern that cannot be formed by screen printing alone. Further, regarding the conductor pattern 2 whose pattern formation has been completed only by screen printing, a photoresist 3 is also formed to protect it from the etching solution. Next, the thick conductor in the area exposed from the photoresist pattern is etched to form a fine pattern 2'' in the thick conductor 2' portion.

Thereafter, by removing the photoresists 3 and 3', a circuit board having a desired conductor pattern is obtained (FIG. 1C and C'). In addition, FIG. 2 A to H are plan views showing each step of an embodiment in which the present invention is applied to the formation of an upper layer conductor pattern of a multilayer wiring board, and FIG. A sectional view taken along line BB' in the figure is shown.

First, a lower conductor 2 is formed on an insulating substrate 1, and then an insulating layer 4 is formed (FIG. 2A and 2B').

Next, the upper layer conductor 5 is formed by screen printing in a region including a desired pattern (Figure 2, opening .'). next,
A photoresist pattern 6 is formed for the purpose of forming a fine pattern of the upper layer conductor (FIG. 2, c and c').

At this time, a photoresist 5 is also formed by screen printing only in areas including the upper layer conductor pattern whose pattern formation has been completed and the lower layer conductor pattern exposed from the insulating layer to protect it from the conductor etching solution. Next, after etching away the thick film conductor exposed from the photoresist using a thick film conductor etchant, the photoresist is peeled off to obtain a two-layer wiring board with the desired conductor pattern (
Figure 2 2, d').

As described above, according to the present invention, it is possible to eliminate waste of thick conductor material and to form fine conductor patterns.

Further, even in a multilayer wiring structure, since the upper layer conductor can be formed without affecting the lower layer conductor, the degree of freedom in pattern design is increased.

[Brief explanation of the drawing]

1A to 1C are plan views showing each process when forming a thick film conductor pattern according to the present invention, and FIGS. 1A to 1C are cross-sectional views taken along line A-A' in each of the above plan views. , FIGS. 2 A to 2 are plan views showing each process when forming the upper layer conductor pattern of a two-layer wiring board according to the present invention, and FIGS. 2 A' to 2' are B-B' in each of the above plan views. It is a cut sectional view. 1... Insulating substrate, 2, 2', 2''... (first layer) conductor wiring, 3, 3', 6... Photoresist, 4
...Insulating layer, 5...Second layer conductor wiring. Figure 1 Figure 2

Claims (1)

[Claims] 1 Forming a first pattern by selectively screen printing and baking a thick film conductor on an insulating substrate, and then photoetching a portion of the thick film conductor to obtain a desired second pattern. Characteristic method for forming thick film conductor patterns.