JPS61102091A - Manufacture of wiring board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is a contact WI that can be used for facsimile, etc.
J=Relates to a method of manufacturing a sensor wiring board.

(Conventional technology) Photoelectric conversion devices used in facsimiles, etc.

As shown in FIGS. 2 and 6, an electrode wiring section (2) is provided on the upper surface of an insulating substrate (1), and a dedicated integrated circuit (4
) is formed with a bonding wiring part (3) for joining them with a bonding wire (5) or the like, and a photoelectric converter electrode (161) made of amorphous silicon or the like is formed at the tip of the electrode wiring part (2). An element part (6) is provided, and a transparent electrode (7) and a metal conductive layer as a photoelectric conversion part common electrode (8) are formed as shown in the figure.

In FIGS. 2 and 3, a metal chromium layer was used for the electrode wiring part (2) because it has good photoelectric conversion characteristics with amorphous silicon.

However, the drawback is that since the metal chromium layer is formed by vapor deposition, it is not suitable to form it thickly, and the metal chromium layer alone may cause pinholes and the like, resulting in insufficient electrical conductivity. On the other hand, since the bonding wiring section (3) is where the dedicated integrated circuit (4) is mounted, gold (Au) is laminated for bonding suitability, durability, and corrosion resistance. However, gold is extremely expensive, and the conventional method of depositing gold on the entire surface of the insulating substrate (1) and then removing unnecessary parts wastes a large amount of gold, which is not desirable. . Moreover, when metal is formed on the surface of the chromium layer, the adhesive strength is weak, and there is a problem that the metal peels off when a peel test is performed using an adhesive tape.

As a way to prevent this, it was considered to interpose a copper layer, silver layer, aluminum layer, etc. that acts as an adhesive layer between the metal chromium layer and the gold layer, but the problem is that gold
It is compatible with the adhesive layer of silver, aluminum, etc., and there is a problem that the gold layer and the adhesive layer diffuse into each other and mix, which has a negative effect on the bonding condition of the integrated circuit. (Problems to be Solved) The present invention has been developed in view of the above-mentioned shortcomings of the prior art.■ To ensure sufficient electrical conductivity in the electrode wiring part.■ To not waste expensive money used in the bonding wiring part. This method aims to solve four problems: (1) the gold layer in the bonding wiring part has sufficient adhesive strength with the underlying layer; and (2) the gold layer in the bonding wiring part does not diffuse and mix with the underlying metal.

(Means for Solving the Problems) In other words, one aspect of the present invention is to form a vapor deposited layer of metallic chromium on an insulating substrate, further layer metallic nickel, and form a gold plated portion in an opening on the surface of the conductive layer. By depositing an insulating film of a photosensitive resin and applying electrolytic gold plating to the opening, a bonding wiring portion consisting of a gold plating layer of a desired shape is formed, and then the insulating film is peeled off,
Next, a corrosion-resistant film is formed to cover the electrode pattern portion, and a desired electrode wiring portion is formed using an etching method.
This is a method of manufacturing a wiring board in which metal chromium is exposed in a photoelectric conversion section.

(Detailed Description of the Invention) The present invention will be described in detail based on FIGS. Although the thickness of each layer in FIGS. 1(a) to (h) is exaggerated as in FIG. For example, a chromium borosilicate glass, quartz glass, or glazed alumina substrate manufactured by Co., Ltd., manufactured by 7059 Co., Ltd. may be used.A metallic chromium film (9) is deposited on the upper surface of this insulating substrate (1) by vacuum evaporation or sputter evaporation. , a metal nickel film (10) is deposited to a thickness of about 0.3 μm, and then a metal nickel film (10) is deposited at o2 to 0.4 μm without contact with the outside air.
Deposit about μm.

Metallic nickel here without exposure to the outside air:! A uO
), when exposed to the outside air, a metallic chromium film, 9
This is because an oxide film is formed on the surface of the metal nickel film α0), which reduces the adhesive strength of the metal nickel film α0) laminated thereon. In order to increase the adhesive strength between chromium and nickel, there is also a method of interposing an adhesive layer such as an aluminum layer or a copper layer between them.

The thickness of the adhesive layer is 0.05 to 0.2 μm for the copper layer.

In the case of an aluminum layer, the thickness is about 0.1 to 06 μm.

When this adhesive layer is interposed, in addition to the advantage of increasing adhesive strength, there is also the effect of increasing the electrical conductivity of the electrode wiring portion (2). In particular, when a copper adhesive layer is used, the gold layer and nickel layer (10) can also be laminated by electrolytic plating.

In any case, if a conductive layer consisting of a small amount of metal chromium film (9) and metal nickel film u01 is formed.

As shown in FIG. 1(b), an insulating film U made of photosensitive resin is applied. The insulating film 0D has a pattern shape, and the opening Q21 is a portion where electrolytic gold plating will be formed in the future. A nonconductive layer of nickel oxide is formed on the surface of this opening 0z when it comes into contact with the outside air. If the next step of electrolytic gold plating is carried out as it is, the adhesion strength with the gold plating layer will be insufficient, so as a pretreatment for electrolytic gold plating, a strong reducing agent such as
Contact with an aqueous solution of about 5 cents by weight, and open the opening u.
It is preferable to roughen the surface of the metal nickel layer α0) of No. 21.

Next, as shown in FIG. 1A, electrolytic gold plating is performed using the conductive layer as a cathode. The thickness of the gold plating film α3 is 0.
．． Approximately 4 to 3.0 μm is appropriate.

By the pretreatment, the adhesion strength of the gold plating film u31 becomes sufficient, and since gold has no compatibility with the underlying nickel film 00), no diffusion phenomenon occurs. This gold plating film 03) becomes a bonding wiring part.

After electrolytic plating, as shown in FIG. 1 (A), the insulating film Uυ of the photosensitive resin is removed using a special stripping solution or the like.

Next, as shown in FIG.
) and the photoelectric conversion part (161) is formed into a pattern using a photosensitive resin using a photographic method.
1 is a bonding wiring part (3) coated with gold plating film 03).
) and the portion that will become the common electrode (8) are also coated with a corrosion-resistant film (2). However, the bonding wiring part (3)
The gold plating film u31 itself becomes a corrosion-resistant film and is durable, and the common electrode (8) can be formed separately in the final process, so the corrosion-resistant film α is not necessarily applied to these parts.
There is no need to apply step 4. However, it is advantageous in terms of process to form the common electrode (8) at this time. In the state shown in Fig. 1 (e), the part not covered with the first corrosion-resistant film α,
That is, when the exposed metal nickel film U■ and metal chromium film (9) are corroded and removed with an etching solution, the first
It becomes a mark as shown in the figure. At this time, the common electrode (
8), the electrode wiring part (2) etc. is the bonding wiring part (3)
It is formed with

After etching, the corrosion-resistant film a4+t;r is removed, resulting in a state as shown in FIG. 1(G). In this state, the photoelectric conversion section electrode (corresponding to 161K) has a metal nickel film of 0.
0) exists, so only the metal nickel is melted here, and a corrosive solution that does not attack gold and chromium is applied.

Examples of such corrosive liquids include nitric acid, perchloric folic acid, and phosphoric acid. In this way, only the exposed metal nickel film α0) is dissolved, resulting in the state shown in FIG. 1 (H). In FIG. However, the present invention is not limited to this. For example, if a gold plating layer is formed on the upper layer of the common electrode (8), the common electrode (8) will be composed of three layers: a gold plating layer, a nickel layer, and a chromium layer. Basically, it is acceptable to form the photoelectric conversion part electrode (+61) with a metal chromium layer (9).Chromium has good photoelectric conversion characteristics with amorphous silicon.

The electrode wiring part (2) consists of at least two layers, a metal chromium film (9) and a metal nickel film 10), and has sufficient conductivity.

As shown in the figure, a gold plating layer (131) may be further added.The bonding wiring part (3) has a gold plating layer αJ.
is necessary.

Examples of the present invention will be described below.

[Example 1] Barium borosilicate glass 7059 manufactured by Corning, USA was used as the insulating glass, and a metallic chromium film was uniformly formed to a thickness of 0.2 μm on its upper surface by sputter deposition, followed by a metallic nickel layer with a thickness of 0.2 μm. A positive photosensitive resin 0FPR800 manufactured by Tokyo Ohka Chemical Co., Ltd., which is laminated to a thickness of .3 μm, is applied over the entire surface, and the gold-plated area is made into an opening by pattern exposure and development using a mask. A foam edge coating was applied. followed by 6% by weight
After being immersed in an aqueous hypophosphorous acid solution for 6 minutes, washed with water and dried, the openings were electrolytically plated with gold. A gold plating layer having a plating thickness of 08 μm was formed in the opening by a normal operation using a potassium gold cyanide plating bath. Next, the above-mentioned insulating film was removed using a specified stripping solution, and the positive photosensitive resin 0FPR was applied again.
800 to form a corrosion-resistant film in the form of an electrode pattern, the metal nickel layer not covered with the corrosion-resistant film was removed by etching with a 10% nitric acid water bath, and the underlying metal chromium layer was etched with ceric nitrate. -Removed using etching solution containing perchlorine. Subsequently, after peeling off the corrosion-resistant film, 10% by weight
When it was immersed in a concentrated nitric acid aqueous solution, the metal nickel layer was removed in the photoelectric conversion section and the metal chromium layer was exposed, yielding a wiring board for a linear sensor. The obtained wiring board did not peel off even in a peel test using an adhesive tape, and the adhesive strength of each layer was good.

[Example 2] In Example 1, after metal chromium was sputter-deposited on the upper surface of the insulating substrate, a metal copper layer with a thickness of 0.1 μm was laminated as an adhesive layer, and then a nickel sulfamate layer was laminated as a metal nickel film. It was formed to a thickness of 0.5 μm using a bath. A mounting board was obtained in the same manner as in Example 1 below.

The obtained wiring board showed no peeling phenomenon even when peeled using an adhesive tape, and the adhesive strength of each layer was good.

(Effects of the Invention) The present invention is a method of manufacturing one or more wiring boards, and according to the present invention, the electrode wiring portion has a two-layer structure of a vapor-deposited film of metallic chromium and a metallic nickel film.

Sufficient electrical conductivity can be maintained, and even if a break in the gold layer or chromium vapor-deposited layer occurs, such as a pinhole, the upper metal nickel film will compensate, so the reliability of conduction will be significantly increased. Furthermore, in the manufacturing method of the present invention, the gold layer of the bonding wiring part is electrolytically plated selectively only in the openings where the insulating film is not coated, that is, in the necessary locations.
Expensive money is not wasted. In addition, the lower layer of the gold plating layer is a metallic nickel layer, and the metallic nickel is
Since it is not compatible with gold, the gold layer does not diffuse and mix with the underlying metal, resulting in a consistently good bonding state.

In addition, the adhesive strength between the gold plating layer and the underlying metal nickel layer is strong, and it exhibits sufficient resistance to peeling tests using cellophane adhesive tape.

Additionally, according to the manufacturing method of the present invention, when performing electrolytic plating of metal, the gold plating layer is applied only to the openings of the insulating coating of the photosensitive resin, but the plated body itself is , since there is a uniform conductive layer consisting of a gold-84 chromium film and a metallic nickel film.

The electric field of electrolytic plating is not localized, so partial gold plating has the additional effect of forming metal with a uniform thickness regardless of the shape of the plating.

[Brief explanation of the drawing]

FIGS. 1A to 1C are explanatory diagrams showing an example of the method for manufacturing a wiring board of the present invention in the order of steps, FIG. 2 is an explanatory cross-sectional view showing an example of a linear sensor, and FIG. FIG. 2 is a partial plan view showing an example of a linear sensor. (11...Insulating substrate (2)...Electrode wiring part (
3)...Bonding wiring part (4)...Dedicated integrated circuit (5)...Bonding wire (6)...Photoelectric element part (power...Transparent electrode (8)...
Common electrode (16)...photoelectric conversion section electrode

Claims (5)

[Claims] (1) On the surface of a conductive layer formed by vapor-depositing at least a metal chromium film and further laminating a metal nickel film on an insulating substrate, an insulating film of photosensitive resin with the gold plating part as an opening is deposited, By applying electrolytic gold plating to the opening, a bonding wiring section made of a gold plating layer of a desired shape is formed, and then the insulating film is peeled off, and a corrosion-resistant film is then applied to cover the electrode wiring section and the photoelectric conversion section. A method for manufacturing a wiring board, in which an electrode wiring part of a desired shape is formed by forming at least a metal chromium film and a metal nickel film by an etching method, and the metal chromium film is exposed in a photoelectric conversion part. (2) The method for manufacturing a wiring board according to claim 1, wherein the metal nickel film is formed by a vapor deposition method. (3) The method for manufacturing a wiring board according to claim 1, wherein the metal nickel film is formed by electrolytic plating. (4) The method for manufacturing a wiring board according to claim 1, wherein an adhesive layer is interposed between the metal chromium film and the metal nickel film. (5) The method for manufacturing a wiring board according to claim 1, wherein the common electrode has a three-layer structure of a gold film, a metal nickel film, and a metal chromium film formed by electrolytic plating.