JPH05152750A - Manufacture of multilayered wiring board - Google Patents

Abstract

PURPOSE:To prevent the occurrence of disconnection between a via hole and metallic wiring pattern and, it the same time, to reduce the number of processes by preventing the formation of a reversely tapered via hole on the wiring pattern. CONSTITUTION:In this high-density multilayered wiring board manufacturing method in which a polyimide film and metallic wiring pattern are formed, a wiring pattern is formed by irradiating a resist film 4 with excimer laser light and a via hole pattern is formed by irradiating a polyimide film 3 with excimer laser light after the films 3 and 4 are formed on the wiring pattern. Then a metallic thin film and a resist film are etched with excimer laser light in a conductor layer forming process. Therefore, the connectability of the wiring pattern can be improved and, accordingly, the manufacturing yield can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used for manufacturing a multilayer wiring board. The present invention relates to a method for manufacturing a multilayer wiring board including a via hole forming step of connecting upper and lower conductor layers of a large-scale integrated circuit (LSI) mounting high-density multilayer wiring board used for electronic equipment such as a computer.

[0002]

2. Description of the Related Art Among conventional methods for producing a multilayer wiring board,
The formation of via holes connecting upper and lower conductor layers in the manufacture of a high-density multi-layer wiring board for mounting large-scale integrated circuits (LSI) used in electronic devices such as computers is particularly shown in FIG.
As shown in FIG. 1, a first step of forming a metal wiring pattern 2 on the substrate 1 and a second step of forming a photosensitive polyimide film 9 on the wiring pattern 2 over the entire surface of the substrate 1 by a spin coating method and drying at a low temperature. Step, a third step of irradiating the photosensitive polyimide film 9 with ultraviolet rays S through a glass mask 10 which shields a predetermined portion, and developing and shielding the photosensitive polyimide film 9 irradiated with the ultraviolet rays S to the shielded portion. The via hole 6 is formed by removing the photosensitive polyimide film 9 at the corresponding portion.
And a fifth step of curing the photosensitive polyimide film 9 to imidize it, a sixth step of forming the metal thin film 7 over the entire surface of the photosensitive polyimide film 9, and a metal thin film 7 A seventh step of forming a resist film 4 on the entire surface of the substrate 1 by a spin coating method and drying at low temperature, and an eighth step of irradiating the resist film 4 with ultraviolet rays S through a glass mask 10 which shields a predetermined portion. And a ninth step of developing the resist film 4 irradiated with the ultraviolet rays S to remove the resist film 4 in the portion irradiated with the ultraviolet rays S,
A tenth step of forming a plating 8 on the portion where the resist film 4 is removed, and an eleventh step of peeling the resist film 4;
And the twelfth step of removing the metal thin film 7 by dry etching.

[0003]

In such a conventional method for manufacturing a multilayer wiring board as described above, in the step shown in FIG. 2B, variations in film thickness within the substrate due to spin coating and temperature inside the substrate due to low temperature drying are performed. There is an effect of variation and
In the process shown in FIG. 2C, the influence of the variation in the exposure amount in the substrate due to the exposure is influenced, and these adverse effects are overlapped.
When the development is performed as shown in (d), the via holes 6 are formed in the substrate.
The via holes of both the side having a positive taper shape (a shape in which the top surface of the hole is wide and the bottom surface is narrow) and the reverse taper shape (a shape in which the top surface of the hole is narrow and the bottom surface is wide) are formed.

When the reverse taper type via hole is formed, in the step of connecting the upper and lower conductor layers, as shown in FIG.
As shown in FIG. 2, the resist remains on the side surface of the via hole of the inverse taper type, and there is a drawback that the upper and lower conductor layers are likely to be cut at the resist remaining portion at the time of plating formation in FIG.

The present invention solves such a problem, and an object of the present invention is to provide a method of manufacturing a multilayer wiring board which can prevent the pattern from being cut due to a resist residue.

[0006]

The present invention is a method of manufacturing a multilayer wiring board in which a polyimide and a metal wiring pattern are formed, the first step of forming a metal wiring pattern on the board, and the above-mentioned wiring pattern. A second step of forming a polyimide film over the entire surface of the substrate and drying at a low temperature, a third step of curing the polyimide film for imidization, and forming a resist film over the entire surface of the substrate on the polyimide film. And a fourth step of drying at low temperature, a fifth step of removing a predetermined portion of the resist film by masking and removing the resist pattern, and a via hole forming portion of the portion where the resist film is removed. Sixth step of removing the polyimide film to form a via hole, a seventh step of forming a metal thin film over the entire surface of the substrate, and the resist It is characterized by being manufactured by an eighth step of removing the upper metal thin film, a ninth step of forming a plating layer on the metal thin film of the via hole portion, and a tenth step of removing the resist film. To do.

The polyimide film can be formed by spin coating, and the resist film, the polyimide film, and the metal thin film on the resist film can be removed by irradiation with excimer laser light.

[0008]

A metal wiring pattern is formed on a substrate, a polyimide film is formed on the wiring pattern over the entire surface of the substrate by a spin coating method, and is dried at a low temperature. Subsequently, the polyimide film is cured and imidized, a resist film is formed on the polyimide film over the entire surface of the substrate by a spin coating method, and is dried at a low temperature.

Next, the resist film is irradiated with excimer laser light through a mask that shields a predetermined portion, the resist film is removed and wiring pattern processing is performed, and the via hole forming portion where the resist film is removed is formed. The polyimide film is also irradiated with excimer laser light through a mask to remove the polyimide film and form a via hole. After forming the via hole, form a metal thin film on the entire surface of the substrate,
Irradiate excimer laser light on the metal thin film part on the resist film through a mask to remove the metal thin film and form a plating layer on the metal thin film in the via hole part, then irradiate the excimer laser light on the resist film. The resist film is removed.

As a result, the reverse taper-shaped via hole is not formed, and it is possible to eliminate the remaining resist, the remaining insulating part from the via hole, and the resulting disconnection, thus improving the product yield. be able to.

[0011]

Embodiments of the present invention will now be described with reference to the drawings. 1A to 1J are cross-sectional views showing an example of the manufacturing process in the embodiment of the present invention.

The manufacturing process in this embodiment is as follows.
As shown in (a), the wiring pattern 2 is formed on the substrate 1. Next, as shown in FIG. 3B, the polyimide film 3 is applied to the entire surface of the substrate 1 by a spin coating method, and low temperature drying is performed in an oven. In this state, the polyimide film 3 has a film thickness of 20 μm to 30 μm and is not imidized yet. The low temperature drying is performed by baking at a temperature of 70 ° C. to 80 ° C. for 40 minutes to 60 minutes.

Next, as shown in FIG. 3C, the polyimide film 3 is cured at 300 ° C. to 400 ° C. for imidization. Subsequently, as shown in FIG. 3D, the resist film 4 is applied on the entire surface of the polyimide film 3 by a spin coating method, and is dried at a low temperature in an oven. The thickness of the resist film at this time is 8 μm to 12 μm, and the low temperature drying temperature is 80 ° C. to 9 μm.
Bake for 60 to 70 minutes at 0 ° C.

Then, as shown in FIG. 2E, the excimer laser light E is scanned through a mask 5 which is partially shielded so that only a desired portion of the surface of the resist film 4 is irradiated with the excimer laser light E. , The resist film 4 is removed,
Performs pattern processing for wiring patterns. The conditions of the excimer laser in this step are a wavelength of 248 nm, an energy density of 0.79 (J / cm ² ), and a Shot number of 35 to 45.

Next, as shown in FIG. 1F, the polyimide film 3 in the via hole forming portion where the resist film 4 has been removed is also scanned with the excimer laser light E through the mask 5 so that the polyimide film 3 is removed. Are removed to form a via hole 6. The condition of the excimer laser in this process is wavelength 2
48 μm, energy density 0.79 (J / cm ² ) and number of shots 75 to 100. By forming a pattern and a via hole under these conditions, a positive taper without residual resist and insulating via hole is formed. Shaped via holes can be formed.

Subsequently, as shown in FIG.
Cr, etc.
A metal thin film 7 such as Pd, Cu or Ti is formed. Further, as shown in FIG. 1H, the metal thin film 7 on the resist film 4 is scanned with the excimer laser light E through a mask 5 that shields a predetermined portion so that the metal thin film 7 is irradiated with the excimer laser light E. The thin film 7 is removed. The conditions of the excimer laser in this step are a wavelength of 248 nm, an energy density of 0.79 (J / cm ² ) and a shot number of 5 to 10.
The etching residue can be reduced by etching the metal thin film under such conditions.

Next, as shown in FIG. 1I, electrolytic plating 8 is performed on the metal thin film 7. Due to the etching effect of the excimer laser light on the resist film, the polyimide film, and the metal thin film up to this step, a wiring pattern having excellent connectivity can be formed. Plating film thickness is 8-12μ
It is formed to about m.

Finally, the resist film 4 is removed as shown in FIG. The excimer laser conditions in this step are the same as those shown in the step (e) of FIG.
m, energy density 0.79 (J / cm ² ), and the number of shots 35 to 45. In addition, peeling residue due to conventional wet etching such as MEK can be eliminated because the resist film is removed by the excimer laser light, and such a process is repeatedly laminated to form a multilayer wiring board.

[0019]

As described above, according to the present invention, after forming a polyimide film and a resist film on a wiring pattern, the resist film is irradiated with excimer laser light to perform processing for the wiring pattern. By irradiating the film with an excimer laser beam to form a via hole, it is possible to eliminate the residual resist, the residual via part in the insulating part, and the disconnection due to the reverse tapered via hole for insulation. There is an effect that an excellent pattern and a via hole can be formed.

Therefore, in the subsequent conductor layer forming step, the connectivity of the via holes between the upper and lower conductor layers can be improved, the pattern opening can be prevented, and the sputtered film can be exposed by the excimer laser light. Since it is removed by etching, there is an effect that a pattern short circuit can be prevented by eliminating the etching residue and the number of steps can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a manufacturing process in an embodiment of the present invention.

FIG. 2 is a sectional view showing an example of a manufacturing process in a conventional example.

[Explanation of Codes] 1 substrate 2 wiring pattern 3 polyimide film 4 resist film 4'resist remaining 5 mask 6 via hole 7 metal thin film 8 plating 8'non-plated area 9 photosensitive polyimide film 10 glass mask

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[Procedure amendment]

[Submission date] November 4, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a manufacturing process in an embodiment of the present invention.

FIG. 2 is a sectional view showing an example of a manufacturing process in an embodiment of the present invention.

FIG. 3 is a sectional view showing an example of a manufacturing process in a conventional example.

FIG. 4 is a sectional view showing an example of a manufacturing process in a conventional example.

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Fig. 2]

[Figure 4]

[Figure 1]

[Figure 3]

Claims (3)

[Claims] 1. A method of manufacturing a multi-layer wiring board for forming a polyimide and a metal wiring pattern, comprising: forming a metal wiring pattern on a substrate; and forming a polyimide film on the wiring pattern over the entire surface of the substrate. And a low-temperature drying second step, a third step of curing and imidizing the polyimide film, a fourth step of forming a resist film on the polyimide film over the entire surface of the substrate and low-temperature drying A fifth step of removing a predetermined portion of the resist film by masking and removing the resist film to process a wiring pattern; and removing the polyimide film in the via hole forming portion of the resist film removed portion to form a via hole. And a seventh step of forming a metal thin film on the entire surface of the substrate, and removing the metal thin film on the resist film. A multi-layer wiring board, which is manufactured by an eighth step, a ninth step of forming a plating layer on the metal thin film in the via hole portion, and a tenth step of removing the resist film. Method. 2. The method of manufacturing a multilayer wiring board according to claim 1, wherein the polyimide film is formed by a spin coating method. 3. The method for manufacturing a multilayer wiring board according to claim 1, wherein the resist film, the polyimide film, and the metal thin film on the resist film are removed by irradiation with excimer laser light.