JPH01214092A - Manufacture of printed wiring board - Google Patents

Abstract

PURPOSE:To prevent a metal plate layer within a through hole from coming off needlessly by etching due to insufficient exposure by forming a resin layer for protecting a resist film having excellent permeability to ultraviolet rays on a photosensitive resist film. CONSTITUTION:A photosensitive resist film 3 is formed by electric deposition on an insulating board 1 on which a through hole 1a and a metal plate layer 2 are provided. A resin layer 4A for protecting a resist film having excellent permeability to ultraviolet rays is formed thereon. Next, the resin layer 4A is exposed from a light source 6 via a mask film 4, and the photosensitive film 3 of the necessary part is hardened, after which the part where the photosensitive resist film is not hardened and the resin layer 4A are removed by development. After that, using the photosensitive resist film 3 left after development as a resist, the metal plate layer 2 of an unnecessary part is removed by etching. Said resin layer 4A is formed, for example, by impregnating the insulating board 1 in an aqueous paint containing resist-film protecting resin and by drying it.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a printed wiring board having a printed pattern formed by etching a metal plating layer.

[Conventional technology]

The second factor is a manufacturing process diagram showing a conventional printed wiring board manufacturing method. They are evenly spaced. 3 is metal plating layer 2
4 is a photosensitive resist film formed on the entire surface of the photosensitive resist film 3 by electrodeposition coating method, 9 is a resin layer for protecting the resist film, 5 is a mask film, 6 is a light source,
7 is ultraviolet light.

Next, the operation will be explained.

First, on the insulating plate 1 having the metal plating layer 2, as shown in FIG.
As shown in a), a photosensitive resist film 3 is formed by electrodeposition. Next, the insulating plate 1 having the photosensitive resist film 3 is immersed in a water-soluble paint of a resin for protecting the resist film,
Thereafter, drying is performed to form a resist film protective resin layer 4 as shown in FIG. 2(b). Next, Figure 2 (
As shown in e), the necessary mask film 5 is placed on the resist film protective resin layer 4, and ultraviolet light is applied from the light source 6 of the scanning exposure machine. A necessary portion of the photosensitive resist film 3 is exposed to I7 and cured.

Next, the unexposed portion of the M&photo resist film 3 and the resist film protective resin layer 4 are removed by development,
Figure 2(d) Make it as shown in K. Subsequently, etching is performed using the remaining photosensitive resist film 3 as a resist, unnecessary metal plating layer 2 is removed, and patterning is performed as shown in FIG. 82(e) to obtain a T printed wiring board.

[Problem to be solved by the invention]

Since the conventional method of manufacturing a printed wiring board is as described above, as shown in FIG. Ninth, the through hole 1a cannot reach the photosensitive resist film 3 and needs to be cured.
The photosensitive resist film 3 inside is removed during the development process without being cured, and the through hole 1 is removed during the next etching process.
There are problems such as a missing part being formed in a part of the metal plating layer 2 in a.

This invention has been made to solve the above-mentioned problems, and provides a method for manufacturing a printed wiring board that can prevent the metal plating layer in the through hole from being unnecessarily removed due to etching due to insufficient exposure. The purpose is to

[Means to solve the problem]

The method for manufacturing a printed wiring board according to the present invention includes forming a photosensitive resist film on a metal plating layer of an insulating board by dip coating or electrodeposition, and forming a resist film protective resin layer on the photosensitive resist film. Then, by exposing the resist film retention resin layer to light through a mask film, the required portions of the μ-photosensitive resist film are cured, and the uncured photosensitive resist film and the resist film protection resin layer are removed by development. Then, using the remaining photosensitive resist film as a resist, unnecessary portions of the metal plating layer are removed by etching.

[Effect]

The type of resin layer forming process in this invention is to provide a resist film protective resin layer, such as acrylic resin, which easily transmits ultraviolet rays, on the photosensitive resist film by dip coating or electrodeposition. Even if the protective resin enters the through hole in a thick state, ultraviolet rays easily pass through it and reach the photosensitive resist film within the through hole, thereby making it possible to reliably cure the photosensitive resist film.

In this way, the metal plating layer inside the through hole will not be chipped due to etching, and a high quality printed wiring board can be manufactured.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. @1
In the figure, 4A is a resist film protection resin layer with good ultraviolet transmittance, and the same components as those shown in FIG.

I will explain the operation shortly.

First, on an insulating plate 1 having a metal plating layer 2 (see FIG. 1),
&) As shown in K, a photosensitive resist film 3 is formed by electrodeposition. Next, the insulating plate 1 having the photosensitive resist film 31 is immersed in a water-soluble paint made of a resist film protective resin such as acrylic with good ultraviolet transmittance, and then dried. As shown in FIG. 3), a resist film protective resin layer 4A is formed. Subsequently, as shown in FIG. 1(c), a mask film 5 is placed on the resist film protective resin layer 4A, and ultraviolet rays 7 are irradiated from the light source 6 to expose the required portions of the photosensitive resist film 3. , harden.

At this time, the resist film protecting resin layer 4A sufficiently transmits the ultraviolet rays T, and the photosensitive resist film 3 is sufficiently exposed.

Next, the unexposed portions of the photosensitive resist film 3 and the resist film protective resin layer 4A are removed by development, and subjected to K as shown in step 11(d). According to this, the photosensitive resist film 3 inside the through hole 1 also remains uniformly due to the above-mentioned sufficient exposure and curing, and even in the subsequent etching process, the metal plated layer 2t is formed inside the insulating plate 1 (7) x through hole 1a. , gl C (e).

In the above embodiments, an acrylic resin was used as the resist film protective resin with good UV transmittance, but any resin that easily transmits UV rays can be used.

Further, in the above embodiment, the insulating plate 1 having the &i photosensitive resist film 3 is immersed in a water-solubilized paint of a resist film protecting resin and then dried, and a resist film protecting resin layer 4 is applied thereon.
The case where Ae is formed is explained, and the ratio is such that a positively or negatively charged resist film protective resin with good ultraviolet transmittance is contained in an electrolytic bath, and the above-mentioned photosensitive resist film 3 is formed on the metal plating layer 2. The resist film protecting resin layer 4A can also be formed by inserting the insulating plate 1 and carrying out the electrodeposition process, and the same effects as in the above embodiment can be achieved.

〔Effect of the invention〕

As described above, according to the present invention, in the process of manufacturing a printed wiring board, a resin film for protecting the resist film is formed using a resin such as acrylic resin with good UV transmittance, so that the resist film buried in the through hole can be protected. This has the effect that the theoretical resin no longer blocks ultraviolet light and that the photosensitive resist film formed in the through hole can be sufficiently exposed and cured.

[Brief explanation of the drawing]

FIG. 1 is a process diagram showing a method for manufacturing a printed wiring board according to an embodiment of the present invention, and FIG. 2 is a process diagram showing a conventional method for manufacturing a printed wiring board. 1 is an insulating plate, 1a is a through hole, 2 is a metal plating layer,
3 is a photosensitive resist film, 4A is a resist film protective resin layer with good ultraviolet transmittance, 5 is a mask film, 6 is a light source,
7 is ultraviolet rays. In the drawings, the same reference numerals indicate the same or equivalent parts. Patent applicant: Mitsubishi Electric Corporation (2 others)

Claims (1)

[Claims] A resist film forming step in which a photosensitive resist film is formed by electrodeposition on an insulating plate having through holes and a metal plating layer, and a resist film having good ultraviolet transmittance is formed on the photosensitive resist film. a resin layer forming step of forming a resist film protective resin layer; a curing step of exposing the resist film protective resin layer from a light source through a mask film to harden necessary portions of the photosensitive resist film; A development step in which the uncured portion of the photosensitive resist film and the resist film protective resin layer are removed by development, and the photosensitive resist film remaining after this development is used as a resist to remove unnecessary parts by etching. A method for manufacturing a printed wiring board, comprising an etching step for removing the metal plating layer in a portion.