JPH06244532A - Exfoliating method for resist - Google Patents

Abstract

PURPOSE:To achieve that a resist film is not left on the surface of a wiring line or the like in a resist exfoliating process which is executed after an etching operation by a method wherein a scribing operation for a figure, a pattern or the like is executed to the surface of a resist to be exfoliated and a treatment by an exfoliating liquid is executed. CONSTITUTION:An organic compound-based, a nonmetal-based or a metal-based resist film 3 as an etching resist is formed on a substrate to be treated. Before the resist is exfoliated, a scribing operation for a figure, a pattern or the like is executed to the surface of the resist to be exfoliated. In the scribing operation, the combination of its slit width, its depth and its interval is contrived. Thereby, the penetration into the resist of an exfoliating liquid and the degree of the subdivision of exfoliated pieces of the resist can be adjusted. In a successive process, the substrate is immersed in the exfoliating liquid, and the exfoliating treatment of the resist is executed. Then, the exfoliating liquid from a part to which the scribing operation has been executed penetrates into the inside of the resist film in the substrate on which the scribing operation has been executed to the face of the resist, the exfoliation of the resist is promoted, and the resist film is stripped from a preform.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist stripping method, and more particularly to a resist stripping method for a printed circuit board.

[0002]

2. Description of the Related Art Generally, in the process of manufacturing a multilayer printed wiring board, various resists are used according to the purpose in order to form a pattern such as a wiring pattern, and the resist is peeled off after the pattern formation. This peeling of the resist is performed by different methods depending on the type of resist used and the like.

For example, in a manufacturing process of a printed wiring board by a pattern plating method, an organic compound resist film is formed on a thermosetting resin copper clad laminate (hereinafter simply referred to as a substrate) which is a composite material formed of resin and copper foil. After forming, the pattern is formed by performing exposure. After that, solder plating is performed on the pattern, and the necessary portion of the copper to be left as the pattern is covered with a metal-based resist film such as solder plating,
Protection is provided to prevent copper dissolution during the etching process. The stripping of the metal-based resist after etching is performed using a stripping solution that selectively removes the metal, in this example, solder.

Also, in the manufacturing process of the printed wiring board by the tenting method, an organic compound type resist is used. That is, in this method, a resist film is formed on a substrate, then exposure is performed to form a pattern, and after etching, the organic compound-based resist is removed. The resist is peeled off by treating with methylene chloride if the resist is a solvent type and using sodium hydroxide if the resist is a water-soluble type.

In the stripping method using a strong acid (mixture of acids) as a stripping solution for removing the organic compound type resist film, a metal type resist or the like is used as an etching resist. After stripping the resist film, it is washed with water and dried. It executes a series of processes.

As another conventional technique for removing the resist film, for example, the technique described in Japanese Patent Laid-Open No. 2-90172 is known.

In this conventional technique, the resist film surface is irradiated with excimer laser light in a vacuum to highly crosslink and alter the resist, and the resist pattern is completely decomposed and removed by an ablation (polishing) action. It is a thing.

[0008]

However, in general, the prior art using a stripping solution as described above is highly cross-linked,
There is a problem that the deteriorated resist cannot be completely peeled off.

Generally, the important factors for efficiently and completely removing the resist while minimizing the influence on the substrate are the type of resist, the type of stripping agent, the type of stripping equipment, the degree of curing and the degree of adhesion of the resist. Therefore, it is necessary to take these into consideration when peeling the resist film. In the above-mentioned conventional technology, it is difficult to fully consider these factors, and it is difficult to completely remove the resist by causing variations in the resist stripping conditions.

When a metal is used as the resist, the resist is peeled off because the metal resist forms a film on the line surface that is not easily corroded by a peeling solution, and other resists such as organic and non-metal resists are used. Since it is stronger than the resist, it has a problem that the peelability is poor and the metal resist is left on the line surface.

When an alkali type resist is used, the resist is stripped using an alkaline solution as a stripping solution. In this case, the stripping time greatly changes depending on the concentration of the alkaline solution which is the stripping solution. However, the size of the peeled pieces of the resist may change, and it is difficult to remove the peeled pieces efficiently.

In this peeling method, the temperature of the peeling liquid also has a great influence on the peeling time.
It is carried out at 50 ° C to 50 ° C. And, this method can shorten the peeling time when the treatment temperature is high, but it has a problem that it causes alkaline burning on the copper surface, which may cause a black coating, and phenol, polyimide, etc. There is a problem that a certain type of substrate is denatured by an alkaline stripping solution.

A method using methylene chloride, which is a chlorine-based organic solvent, is used for peeling the solvent-type resist, but the chlorine-based organic solvent may attack the epoxy resin, and the resist is removed in a short time. It has a problem that it is necessary.

Further, there is a method of stripping a resist using a strong acid. However, since this method uses concentrated sulfuric acid or the like as a stripping solution, the resist is stripped in a relatively large thin piece or sheet, and stripping pieces are stripped in stripping equipment. However, there is a problem that it is difficult to efficiently recover.

As described above, organic compound type, non-metal,
There are many types of stripping solutions used for stripping metal-based resists. And for peeling the organic compound-based resist,
A chlorine-based organic solvent such as methylene chloride or an alkaline solution such as sodium hydroxide is used, and a strong acid such as sulfuric acid or a stripping solution for selectively removing the metal is used for stripping a non-metal or metal-based resist.

As described above, in the resist stripping method using the stripping solution, there are various choices of stripping solutions, and the use of these stripping solutions is restricted in relation to global environmental problems. It has a problem that it contains chemicals such as chlorine-based organic solvents that have been used.

Further, in the peeling method using plasma, by exposing the resist to a plasma atmosphere, a temperature of 450.degree.
Although the resist is ashed and peeled at a temperature of 550 ° C., there is a problem in that peeling conditions need to be changed depending on the degree of curing and adhesion of the resist. And
Plasma is used for smear removal, removal of fine resist pieces dispersed on the substrate after resist removal, and the like. For this reason, the method using plasma has a problem that it is difficult to apply to a printed wiring board whose base material is an organic material and is not practical.

That is, the resist stripping method using plasma has a problem that the selection of processing conditions in the resist stripping step is complicated and difficult, which hinders stable production of printed wiring boards.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a resist stripping method in which a resist film is not left on the surface of a wiring line or the like in a resist stripping step performed after etching. Especially.

[0020]

According to the present invention, the above-mentioned object is a method for removing organic compound-based, non-metal-based and metal-based resists, and markings such as figures and patterns on the surface of the resist to be removed. It is achieved by applying.

The resist stripping conditions are as follows:
It depends on the type of stripping agent, the type of stripping equipment, the degree of curing of the resist, the degree of adhesion, etc., but by marking the resist with figures, patterns, etc. By devising the combination of the above, it is possible to eliminate the variation in the stripping condition, minimize the influence on the base material, and efficiently strip the resist.

[0022]

The stripping of the resist according to the present invention is carried out after the resist film has been formed in the same manner as in the conventional case, and then exposed to form a pattern and etched. Organic compound-based, non-metal and metal-based resists are formed on the processed substrate as etching resists.

Before the resist is peeled off, the surface of the resist to be peeled off is scribed with figures, patterns and the like. In this scribe, the combination of the width, depth and interval of the slit is devised, whereby the penetration of the stripping solution into the resist and the degree of fragmentation of the stripped pieces of the resist can be adjusted.

In the subsequent step, when the resist is stripped by immersing the substrate in the stripping solution, the substrate having the resist surface marked is marked with the stripping solution from the scratched portion. By penetrating into the inside of the film, the peeling of the resist is promoted and the resist coating is peeled from the base material (in this case, copper).

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a resist stripping method according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram for explaining an embodiment of the present invention. In FIG. 1, 1 is a resist film, 2 is a copper foil, and 3 is a base material.

The method of one embodiment of the present invention shown in FIG. 1 is an example in which the present invention is applied to a step of producing a printed wiring board by a tenting method. Hereinafter, referring to FIG.
A process for manufacturing a printed wiring board including the method for removing a resist according to the present invention will be described.

(1) As a substrate on which a pattern such as wiring is formed by the tenting method, a substrate to be processed in which a base material 3 and a copper foil 2 are laminated is prepared. A resist is applied on the copper foil 2 of this substrate to form a resist film 1. As the resist, for example, a solvent type resist T- manufactured by DuPont
1220 is used [FIG. 1 (a)].

(2) A pattern such as a wiring pattern is exposed to form a pattern of a resist film [FIG.
(B)].

(3) The copper foil 2 other than the portion where the pattern of the resist film is present is removed by etching. As a result, a pattern of the copper foil with the resist remaining on its upper surface is formed [FIG. 1 (c)].

(4) Scribing with a slit width of 150 μm, a slit interval of 500 μm, and a slit depth of 50 μm is applied in a grid pattern on the resist surface on the pattern with a cutter, a laser beam or the like [FIG. 1 (d)].

(5) The wiring board which has been subjected to the scribing process is immersed in a resist stripping solution, which is a methylene chloride solution in one embodiment of the present invention, to strip the resist film 1 on the pattern and dry it. As a result, a wiring board having a copper pattern is completed [Fig. 1 (e)].

In the above-described one embodiment of the present invention, the marking on the resist surface on the pattern was carried out by a cutter, a laser beam or the like.
It can be carried out by a processing method including polishing, melting, vaporization and marking, and can also be carried out by using a scribing needle, a cutting machine, a knife or the like.

Further, the slit width, the slit interval, and the slit depth of the scribe can be arbitrarily set according to the type of resist used, the type of stripping solution, and the like. The depth of the slit is optimal to reach the surface of the copper foil 2 below the resist film 1, that is, the depth corresponding to the thickness of the resist film 1, but scratches on the surface of the copper foil 2 are The depth may be slightly shallower than this depth if a problem occurs after the treatment.

In this scribing, a solid figure, a plane, a line, a point, and some of these are gathered, a plane figure whose elements are all on the same plane, or the elements are not all on the same plane. Elevated figures, or various shapes that create dyes, fabrics, sewing, sculptures, etc., are formed so that shapes of patterns, patterns, patterns, objects, etc. are patterned patterns.

In addition, although the above-described embodiment of the present invention has been described with reference to the drawings in which the resist film on one pattern is peeled off, the present invention shows that the resist film on the entire substrate is scribed, The resist can be stripped.

In this case, the fineness of the above-mentioned figures, patterns, etc., that is, the linear density of the slits in the peripheral portion of the substrate to be processed and other portions is changed, for example, the scribing density in the peripheral portion of the substrate is changed. By making the height higher than the central portion, it is possible to make the resist stripping time uniform over the entire substrate to be processed.

According to the above-described embodiment of the present invention, when the resist is peeled off in the manufacturing process of the printed wiring board or the like, the organic compound type, non-metal type and metal type resists are marked with figures, patterns and the like. By also, by devising the combination of the slit width of the scribe, the slit interval, and the slit depth, the variation in the stripping condition of the resist is eliminated, and the influence of the stripping solution on the substrate is minimized. The resist can be stripped efficiently and completely.

As a result, in one embodiment of the present invention, since the resist coating does not remain on the substrate, it is possible to eliminate factors that impair the reliability of the multilayer printed wiring board, etc. It is possible to reduce the amount of chlorine-based organic solvents and other chemicals used that are related to environmental problems.

Although the above-described embodiment of the present invention has been described as being applied to the production of the substrate by the tenting method, the present invention can also be applied to the production of the substrate by the pattern plating method. .

[0041]

As described above, according to the present invention, in the resist stripping process performed after etching, the resist can be stripped completely so that the resist film does not remain on the surface of the wiring line or the like.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an embodiment of the present invention.

[Explanation of symbols]

 1 Resist film 2 Copper foil 3 Base material

Claims (5)

[Claims] 1. A resist stripping method for stripping an organic, non-metallic or metallic resist, wherein the surface of the resist to be stripped is marked with a figure, pattern or the like and treated with a stripping solution. And a method for removing the resist. 2. The scribing is performed by a processing method including cutting, punching, polishing, melting, vaporizing or marking, using a cutter, a laser beam, a scribing needle, a cutting machine, a knife or the like. The method of stripping a resist according to claim 1. 3. The scribing is a plane figure in which solids, planes, lines, points, and some of these are gathered, all the elements of which are on the same plane, or the elements are not all on the same plane. It is characterized by being formed into an elevational figure or various patterns that create dyes, fabrics, sewing, sculptures, etc., patterns, patterns, patterns, patterns The method for stripping a resist according to claim 1. 4. The resist stripping method according to claim 1, wherein the scribe has the slit width, slit spacing, and slit depth set arbitrarily. 5. The resist stripping according to claim 1, wherein the scribes have different scribe densities depending on the position in the substrate which is the object to be treated. Method.