JPH08213737A - Conductor formation method - Google Patents

Abstract

(57) [Summary] [Purpose] To enable formation of a more precise wiring pattern of thick film conductors on a ceramic multilayer substrate. [Structure] The thick film conductor paste 1 is printed on one surface of a ceramic substrate 2 and dried (Fig. (A)). At this time, the conductor is not fired. A photosensitive resin 4 is formed on the thick film conductor paste 1 and photo-etched into a wiring pattern shape (FIGS. (B) and (c)). When the unnecessary thick film conductor paste is removed using the cured photosensitive resin 4 as a mask, the state shown in FIG. When the conductor is fired here, the photosensitive resin 4
Is removed, and a fine wiring pattern can be formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a conductor on a ceramic substrate, and in particular, to improve it so that a finer wiring pattern can be easily formed.

[0002]

2. Description of the Related Art In recent years, with the miniaturization of electronic devices and the digitization of circuits, high density circuit boards have been required. Along with this, circuit patterns are required to have finer pitch lines.

Conventionally, a thick film conductor on a ceramic substrate is formed by printing a thick film paste on a desired wiring pattern by a screen printing method, followed by drying and firing.

[0004]

However, it is difficult to form a fine wiring pattern with a fine pitch by the above-mentioned conventional method of forming a thick film conductor by screen printing. Particularly, in the wiring pattern of 100 μm or less lines,
We could not mass-produce it stably.

The present invention solves such a problem, and an object thereof is to make it possible to form a finer wiring pattern of a thick film conductor on a ceramic substrate.

[0006]

The conductor forming method of the present invention for solving the above problems is as follows. That is, a thick film conductor paste is printed on one surface of a ceramic substrate and dried. At this time, the conductor is not fired. Then, a photosensitive resin is formed on the entire surface of the thick film conductor paste, and the photosensitive resin is photoetched so as to leave a wiring pattern. Then, using the cured photosensitive resin on the remaining wiring pattern as a mask, unnecessary thick-film conductor paste other than the wiring pattern is removed. After that, by baking the thick film conductor paste, the photosensitive resin on the wiring pattern is removed, and a thick film conductor can be obtained.

[0007]

In the above method, the photosensitive resin photo-etched into the wiring pattern shape is used as a mask to remove the unnecessary thick film conductor paste to obtain the wiring pattern.
It is also possible to form a finer wiring pattern with a narrower pitch than screen printing.

[0008]

Embodiments of the conductor forming method of the present invention will be described below with reference to the drawings. 1A to 1C show process diagrams of a conductor forming method according to an embodiment of the present invention.

First, in FIG. 1A, the ceramic substrate 2
A commercially available thick film paste 1 of Ag / Pd is printed on one side and dried at 150 ° C. for 10 minutes.

Then, as shown in FIG. 1B, a photosensitive resin 4 is applied to one surface of the thick film paste 1, and a mask 3 is left on the photosensitive resin 4 so as to leave a wiring pattern thereon, and light is irradiated. Mask 3 and uncured photosensitive resin 4 underneath
By removing, the photosensitive resin 4 photoetched into the shape of the wiring pattern can be formed on the thick film conductor paste 1 as shown in FIG.

If liquid honing is performed using a mixture of water and alumina powder in the state shown in FIG. 6C, the cured photosensitive resin 4 serves as a mask, and as shown in FIG. The thick film conductor paste 1 other than the above is removed, and the thick film conductor paste can be obtained only on the wiring pattern. A method using sand blast or water pressure may be used to remove unnecessary thick film conductor paste.

When the firing is performed at 850 ° C. after the patterning is completed as described above, the photosensitive resin 4 on the thick film conductor paste 1 is removed and the delicate thick film conductor is fired, as shown in FIG. To be done.

[0013]

As described above, according to the conductor forming method of the present invention, it is possible to easily form even a fine and narrow pitch wiring pattern on a ceramic substrate, which is difficult by screen printing using a thick film conductor paste. .

[Brief description of drawings]

FIG. 1 is a process diagram showing a conductor forming method of the present invention.

[Explanation of symbols]

 1 Printed and dried thick film conductor paste 2 Ceramic substrate 3 Mask 4 Photosensitive resin

Claims (1)

[Claims] 1. A step of printing a thick film conductor paste on one surface of a ceramic substrate and drying it, and a step of printing a photosensitive resin on the thick film conductor paste on one surface thereof, leaving a desired wiring pattern, and exposing the photosensitive film. Of the conductive resin by photo-etching, the photosensitive resin cured on the wiring pattern is used as a mask to remove unnecessary thick film conductor paste other than the wiring pattern, and the cured photosensitive resin is removed by firing. And a step of obtaining a thick film conductor.