JPH05243709A - Manufacture of printed wiring board - Google Patents

Abstract

PURPOSE:To reduce breaking of discontinuity and defects by forming a conductive resin layer on a photosensitive resin film to prevent static electricity and hence deposition of foreign objects, in view of the fact that the photosensitive resin layer easily accumulates static electricity since it has no conductivity, and thus foreign objects deposit on portions of the photosensitive resin layer and these portions are not exposed to light at the time of exposure, which causes discontinuity of the wiring and defects. CONSTITUTION:A copper-clad insulating substrate 1 is coated with a positive photosensitive resin film 8 by electrodeposition, and then the insulating substrate 1 is coated with a conductive resin and dried, thereby obtaining a conductive resin layer 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a printed wiring board.

[0002]

2. Description of the Related Art In general, manufacturing of a through-hole printed wiring board (hereinafter referred to as T / H PWB) is performed with reference to FIGS.
The tenting method shown in FIG. 8B is often used. According to this method, as shown in FIG. 7A, the conductor layer 2 including the copper plating layer and the through hole ( Hereinafter, referred to as T / H) 1a is formed on the insulating substrate 1 shown in FIG.
As shown in FIG. 7B, the photosensitive resin layer 3 is attached, and a desired wiring circuit pattern is printed with ultraviolet rays through the mask film 4 as shown in FIG. 7C.

Next, as shown in FIG. 7D, the photosensitive resin layer 3 in the unexposed portion is removed with a developing solution to obtain etching resists 5a and 5b. Further, as shown in FIG. 8A, after the exposed conductor layer 2 is removed by etching, finally, as shown in FIG.
As shown in (b), the etching resists 5a and 5b are peeled and removed to obtain T / H PWB.

Further, in the hole filling method shown in FIGS. 9A to 10C, the conductor layer 2 including the copper plating layer and the T / H 1a are formed on the insulating substrate 1 as shown in FIG. 9A. As shown in FIG. 9B, the hole filling ink 7 is filled and cured in the T / H of the formed substrate, and the photosensitive resin layer 3 is attached to the surface of the insulating substrate 1. As shown in FIG. 9D from above, a desired wiring pattern is printed with ultraviolet rays through the mask film 4.

Next, as shown in FIG. 10A, the photosensitive resin layer 3 in the unexposed portion is removed with a developing solution to obtain etching resists 5a and 5b. Further, as shown in FIG.
After removing the exposed conductor layer 2 by etching, FIG.
As shown in (c), the etching resists 5a and 5b and the hole filling ink 7 are peeled and removed to obtain T / H PWB. In this method, instead of the etching resists 5a and 5b formed by the photosensitive resin layer 3, an image formed by screen printing can be used as the etching resist.

In addition to this, the electrodeposition coating method of the positive type photosensitive resin shown in FIGS.
As shown in FIG. 11A, a positive photosensitive resin film 8 is formed on the surface of the insulating substrate 1 in which a conductor layer 2 including a copper plating layer and a through hole 1a are formed on the insulating substrate 1 as shown in FIG. 11B. After coating the coating and drying, from above, see FIG. 11 (c).
As shown in FIG. 5, a desired wiring circuit pattern is printed with ultraviolet rays through the mask film 4.

Next, as shown in FIG. 11D, the positive photosensitive resin film 8 in the exposed portion is removed with a developing solution to obtain etching resists 5a and 5b. Further, as shown in FIG. 12A, the exposed conductor layer 2 is removed by etching, and finally, as shown in FIG.
T / H PWB is obtained by peeling and removing a and 5b.

[0008]

However, in any of the construction methods, the photosensitive resin layer 3 and the positive type photosensitive layer are used in the steps of FIGS. 7 (b), 9 (c) and 11 (b). There is a problem that foreign matter due to static electricity adheres to the surface of the resin film 8 and is not exposed when exposed through the mask film, which causes disconnection and defective defects.

An object of the present invention is to provide a method for manufacturing a printed wiring board in which no foreign matter is attached due to static electricity and there is no disconnection or defective defect due to unexposed light.

[0010]

A method of manufacturing a printed wiring board according to the present invention comprises a step of forming a hole in a copper-clad insulating substrate and a step of forming a copper plating layer in the hole and the surface of the copper-clad insulating substrate. A step of forming a photosensitive resin layer on the surface of the copper plating layer, a step of forming a conductive resin layer on the photosensitive resin layer, and a mask film contacting the conductive resin layer on a predetermined surface A step of exposing the pattern of the wiring circuit, a step of selectively removing the photosensitive resin layer in the unexposed portion by development,
A wiring circuit is obtained including a step of removing the copper portion exposed by development by etching and a step of removing the remaining photosensitive resin layer.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 (a) to 2 (c) show the first embodiment of the present invention.
6A to 6D are cross-sectional views showing the steps in order of explaining the embodiment of FIG.

In the first embodiment, first, as shown in FIG. 1A, a hole is drilled in the insulating substrate 1 and then the conductor layer 2 is formed. As the material of the insulating substrate 1, for example, a glass cloth-based epoxy resin plate or a glass-based polyimide resin plate can be used.

Next, as shown in FIG. 1B, a photosensitive resin layer 3 is formed.

Next, as shown in FIG. 1C, a conductive resin layer 9 is formed by a roller coating method. As the conductive resin layer 9, there is a polyacetylene resin, which can be applied by dissolving it in a solvent such as acetone and applying it by a spray coating method, a brush coating method or the like. The film thickness is 0.2 to 2
μm is suitable.

Next, as shown in FIG. 1D, a desired wiring circuit pattern is printed by exposure through the mask film 4.

Next, as shown in FIG. 2 (a), the etching resists 5a, 5 are developed by developing with a developing solution such as an aqueous solution of sodium carbonate.
b is formed.

Next, as shown in FIG. 2B, the exposed copper portion of the conductor layer 2 is removed by etching.

Next, as shown in FIG. 2 (c), the etching resists 5a and 5b are removed by using a chemical such as sodium hydroxide to form a wiring circuit 6, and the T / T of the first embodiment is used.
To obtain HPWB.

FIGS. 3A to 4C are sectional views showing the second embodiment of the present invention in the order of steps.

In the second embodiment, first, as shown in FIG. 3A, a conductor layer 2 including a copper plating layer and a T / H are formed on an insulating substrate 1.
1a is formed.

Next, as shown in FIG. 3B, the insulating substrate 1
The T / H inside is filled with the hole-filling ink 7 and cured.

Next, as shown in FIG. 3C, the insulating substrate 1
The photosensitive resin layer 3 is attached to the surface. The conductive resin layer 9
There is a polyacetylene resin, which can be dissolved in a solvent such as acetone and applied by a spray coating method, a brush coating method or the like. The film thickness is 0.2 to 2 μm.
Is appropriate.

Next, as shown in FIG. 3D, a conductive resin layer 9 is formed on the photosensitive resin layer 3 by a roller coating method or the like.

Next, as shown in FIG. 3E, a desired wiring pattern is printed with ultraviolet rays through the mask film 4.

Next, as shown in FIG. 4A, the photosensitive resin layer 3 in the unexposed portion is removed with a developing solution to form etching resists 5a and 5b.

Next, as shown in FIG. 4B, the exposed copper portion of the conductor layer 2 is removed by etching.

Next, as shown in FIG. 4C, the etching resists 5a and 5b and the hole-filling ink 7 are removed by using a chemical such as sodium hydroxide, and the T of the second embodiment is removed.
/ HPWB.

5 (a) to 6 (c) are sectional views showing the third embodiment of the present invention in the order of steps.

In the third embodiment, first, as shown in FIG. 5A, a conductor layer 2 including a copper plating layer and a T / T layer are formed on an insulating substrate 1.
H1a is formed.

Next, as shown in FIG. 5B, the insulating substrate 1
The positive photosensitive resin film 8 is electrodeposited on the surface and dried.

Next, as shown in FIG. 3C, the conductive resin layer 9 is formed by the roller coating method.

As the conductive resin layer 9, there is polyacetylene resin, which can be applied by dissolving it in a solvent such as acetone and applying it by a spray coating method, a brush coating method or the like. Further, the suitable film thickness is 0.2 to 2 μm.

Next, as shown in FIG. 5D, a desired wiring circuit pattern is printed on the conductive resin layer 9 through the mask film 4 with ultraviolet rays.

Next, as shown in FIG. 6A, the positive photosensitive resin film 8 in the exposed portion is removed with a developing solution to form etching resists 5a and 5b.

Next, as shown in FIG. 6B, the exposed conductor layer 2 is removed by etching.

Next, as shown in FIG. 6C, the etching resists 5a and 5b are removed by using a chemical such as sodium hydroxide to obtain the T / H PWB of the third embodiment.

[0037]

As is apparent from the above description, according to the present invention, a conductive resin layer is formed on a photosensitive resin layer or a positive type photosensitive resin film, and exposure and etching are performed. It is possible to prevent foreign matter from adhering to the photosensitive resin layer or the positive type photosensitive resin film due to static electricity, and to reduce disconnection and defective defects due to unexposed light.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a process sequence of a first embodiment of the present invention.

2A to 2D are cross-sectional views showing a process sequence for explaining the first embodiment of the present invention.

3A to 3D are cross-sectional views showing a second embodiment of the present invention in the order of steps.

4A to 4D are cross-sectional views showing a second embodiment of the present invention in the order of steps.

5A to 5C are sectional views showing a process sequence for explaining a third embodiment of the present invention.

6A to 6C are cross-sectional views showing a process sequence for explaining a third embodiment of the present invention.

7A to 7C are cross-sectional views showing a method of manufacturing a printed wiring board by a conventional tenting method in order of steps.

FIG. 8 is a cross-sectional view showing a method of manufacturing a printed wiring board by a conventional tenting method, in the order of steps.

FIG. 9 is a cross-sectional view showing the method of manufacturing a printed wiring board by a conventional hole filling method in the order of steps.

FIG. 10 is a cross-sectional view showing a method of manufacturing a printed wiring board by a conventional hole filling method in the order of steps.

FIG. 11 is a cross-sectional view showing, in the order of steps, a method of manufacturing a printed wiring board by a conventional positive-type photosensitive resin electrodeposition coating method.

FIG. 12 is a cross-sectional view showing the order of steps for explaining a conventional method for manufacturing a printed wiring board by electrodeposition coating of a positive photosensitive resin.

[Explanation of symbols]

 1 Insulating Substrate 1a T / H 2 Conductor Layer 3 Photosensitive Resin Layer 4 Mask Film 5a, 5b Etching Resist 6 Wiring Circuit 7 Hole Filling Ink 8 Positive Photosensitive Resin Film 9 Conductive Resin Layer

Claims (1)

[Claims] 1. A step of forming a hole in a copper-clad insulating substrate, a step of forming a copper plating layer in the hole and the surface of the copper-clad insulating substrate, and forming a photosensitive resin layer on the surface of the copper plating layer. A step of forming a conductive resin layer on the photosensitive resin layer, a step of exposing a predetermined wiring circuit pattern by contacting a mask film on the conductive resin layer, and an unexposed portion by development. And a step of selectively removing the photosensitive resin layer, a step of removing the copper portion exposed by development by etching, and a step of removing the remaining photosensitive resin layer to obtain a wiring circuit. And a method for manufacturing a printed wiring board.