JPH116083A - Dissolving liquid for copper or copper alloy, its production, etching, chemical polishing and forming method of copper and copper alloy, and production of printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an oxidizing and dissolving liquid which can be used for both of an etching process and a polishing process by incorporating an oxidizing agent and a coordinate compd. as a compd. which coordinates with uni- or bivalent copper ion so as to give characteristics as a chemical polishing liquid to a copper etching liquid. SOLUTION: This dissolving liquid for copper and copper alloy contains a coordinate compd. as a component of the dissolving liquid, so that copper ion dissolved from the objective body does not react with chlorine ion to produce copper chloride having low solubility but forms a complex having high solubility with water. As a result, deposition of copper chloride on the surface of the objective body is not caused. The complex forming reaction is accelerated in the presence of the chlorine ion under acid conditions, which accompanies acceleration of elution of copper. The dissolving liquid has high resistance against mixing of chlorine. Therefore, hydrogen peroxide or peroxodisulfate can be used as an oxidizing agent. The obtd. liquid can be used as a chemical polishing agent which can be easily controlled, has high safety and is preferable from the environmental and hygienic viewpoints.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the chemical dissolution of copper or a copper alloy, and relates to a chemical dissolution of copper or a copper alloy and a method for producing the same, and a solution of a molded product made of copper or a copper alloy. The present invention relates to a chemical polishing method and a forming method, and a method for manufacturing a printed wiring board provided with wiring made of copper or a copper alloy.

[0002]

2. Description of the Related Art The technology of chemically melting copper or copper alloys is used in a wide range of fields, and is not limited to the production of wind instruments, statues, ornaments, and copper plates. It is an indispensable technology in the field of manufacturing electronic and electrical components such as products (flip chip elements, lead frames, etc.) and printed wiring boards. When applied to these various fields, the components and compositions of the liquids and the processing conditions are optimized according to the purpose of use and the workpiece, respectively. They can be roughly divided into strains.

As shown in FIG. 2, chemical polishing is performed by dissolving and removing the surface of a substrate 9 to which dirt 7 is attached or irregularities 8 are present using a dissolving liquid, thereby obtaining a smooth surface. The material 10 is obtained. Also, the etching process,
As shown in FIG. 3, an etching resist 11 having a predetermined pattern is formed on the surface of the base material 9, and an exposed portion of the base material 9 that is not covered with the resist 11 is dissolved and removed using a dissolving solution. , To obtain a molded body 12 having a desired shape.

[0004]

The etching process and the chemical polishing process use two types of completely different systems in practical use, although both use an approximate chemical reaction phenomenon of oxidative dissolution of metal. This is performed with a processing solution. For example, manufacturing process of precision machine parts and electronic parts (shown in FIG. 4)
Then, after roughening the surface of the copper base material 9 by chemical polishing, the resist film 4 having a predetermined pattern is formed on the surface of the roughened surface 14, and the desired concave portion 15 is formed by etching. Often, both an etching step and a chemical polishing step are performed. In such a manufacturing process, it is necessary to prepare two or more different treatment liquids for use in the respective steps of chemical polishing and etching, and two or more treatment liquids for oxidative dissolution treatment of the same metal. Liquids have to be managed and drained, and they have to cost double.

Accordingly, a first object of the present invention is to provide an oxidized solution that can be used for both etching and polishing.

For a long time, nitric acid-based or chromic acid-based solutions have been used for chemical polishing of copper or copper alloys. These solutions generate toxic gases (nitrite gas) during the work. Since a large amount of hazardous waste (hexavalent chromium) is generated after the work, in recent years, a chemical polishing solution of a hydrogen peroxide-mineral acid system, particularly a hydrogen peroxide-sulfuric acid system, which is safer and preferable for environmental health, has been used. It has come to be.

For example, Japanese Patent Publication No. Sho 51-28565,
JP-A-49-36546, JP-A-49-9322
No. 6, JP-A-49-98731, JP-A-49-98731
JP-A-109223, JP-A-49-122432, JP-A-52-21222, JP-A-52-22
No. 192, JP-A-3-193886, JP-A-6-179988 and the like disclose phosphoric acid, aliphatic alcohols, aliphatic alcohols in a hydrogen peroxide-mineral acid (hydrogen peroxide-sulfuric acid) mixture. Addition of additives such as amines, carboxylic acids, azoles, borate ions, and surfactants suppresses the decomposition of hydrogen peroxide, or simplifies bath management by adjusting the viscosity of the solution. Techniques for prolonging the life and achieving efficient gloss processing have been proposed.

However, when chlorine or chloride ions are mixed in the chemical polishing liquid based on the above-cited technology, even if the amount is small (about 10 ppm), the polishing action is almost lost and the bath life is reduced. Also has the drawback that it tends to be significantly shorter. Therefore, industrial water or tap water cannot be used as a building bath source water for the hydrogen peroxide-mineral acid chemical polishing agent, and deionized water must be used. This point
This is a factor that hinders the spread of chemical polishing in the forming and manufacturing of copper or copper alloys.

As a technique for solving this problem, Japanese Patent Laid-Open No.
In JP-A-9-104840 and JP-A-1-159385, a composition of a hydrogen peroxide-mineral acid-based chemical polishing agent that works effectively even in the presence of chloride ions has been proposed.
There is still room for improvement in practicality. For example, in the former technique, the amount of chlorine contamination is limited to about industrial water or tap water (about 50 ppm at maximum). Therefore, chlorine adheres to the surface of the workpiece, or a chemical containing chlorine is used as a pretreatment for processing, and 100 ppm is added to the polishing bath.
If chlorine is mixed in beyond this, the polishing action is completely lost. In the latter technology, a maximum of 3% by weight (1 mol /
L) The polishing action is maintained up to the chloride ion concentration of about
It is necessary to strictly control and manage the concentration of each component of the non-dissociated phosphate, phosphate ion, monohydrogen phosphate ion and dihydrogen phosphate ion in the bath and the relative concentration ratio based on a specific calculation formula. Further, the control range of the pH of the bath is limited to a relatively narrow range of 1.25 to 3, and the bath is not practically high in terms of bath management.

[0010] However, a chemical polishing solution of a hydrogen peroxide-mineral acid type or a peroxodisulfate type has excellent properties in terms of safety and environmental hygiene. Accordingly, a second object of the present invention is to provide a chemical polishing liquid which has high resistance to the incorporation of chlorine or chloride ions and can use hydrogen peroxide or peroxodisulfate as an oxidizing agent.

It is also possible to utilize the oxidative dissolution of copper in a hydrogen peroxide-mineral acid (hydrogen peroxide-sulfuric acid) mixture as an etching solution, and to actually use the hydrogen peroxide-mineral acid. A series of copper etching solutions are also commercially available. However, it is rather rare to use a hydrogen peroxide-mineral acid or peroxodisulfate solution for copper etching, and an iron chloride or copper chloride solution is mainly used. This is because hydrogen peroxide-mineral acid or peroxodisulfate solution has better etching uniformity, bath life, bath stability, cost, and easier handling than iron chloride or copper chloride solution. This is because the method is inferior in practicality in terms of, for example,

A technique for solving these problems and imparting practicality to a hydrogen peroxide-mineral acid etching solution is disclosed in Japanese Patent Application Laid-Open No. 58-1983.
This is proposed in Japanese Patent Publication No. 110677 and Japanese Patent Publication No. 8-3149. The techniques described in these publications are based on side etching (etching on the side surface of a concave portion generated by etching, ie, etching of an aqueous solution of ammonium persulfate by adding a specific concentration of chloride (such as ammonium chloride or sodium chloride) to an etching solution. While suppressing etching in the direction parallel to the surface to be etched)
The purpose is to improve the etching rate and the etching uniformity, or to prolong the life of the etching bath. However, in the method using the chloride, copper chloride is deposited on the surface of the workpiece, causing new problems such as darkening of the workpiece and deterioration of characteristics (electrical conductivity and thermal conductivity).

Therefore, the present invention is to provide a practical etching solution which is excellent in etching uniformity, bath life, bath stability, cost, ease of handling and does not cause discoloration of the surface of a workpiece. The purpose of.

In the field of copper or copper alloy processing, particularly when processing fine shapes, a copper base material is generally processed by a series of processes as described below. That is, a resist is formed on a copper base material that is a workpiece, patterned, and after selectively etching the exposed copper base material that is not covered with the resist pattern, the resist is removed. It is a series of processes.

When processing copper by this process,
A resist fragment may remain on the copper pattern obtained after the resist is stripped. In particular, when forming a fine pattern,
When the step of roughening the surface of the copper base material before the formation of the resist is performed for the purpose of improving the resist adhesion, the resist fragments are likely to remain on the fine concave surface formed on the surface of the copper base material.

The remaining resist fragments cause various problems such as poor appearance, contamination of the next process, and deterioration of the properties of the workpiece (electrical conductivity and thermal conductivity). In particular, the electronic and
When manufacturing electrical circuits, poor wiring yields and abnormal plating due to residual resist fragments, erroneous detection in the inspection process, or soldering failures are caused. Worsen.
Therefore, in order to avoid such residue of the resist, it is common to strengthen the resist stripping condition.However, since the resist stripping is performed under an alkaline condition under heating, the strengthening of the resist stripping condition is performed by discoloring the copper base material surface. Another problem often arises (so-called alkali burn).

Accordingly, the present invention provides a method for forming (working / manufacturing) a copper or copper-plated molded product, particularly a fine molded product.
A method for forming a molded body capable of avoiding problems caused by remaining resist, and a structure including a molded body made of copper or a copper alloy using the molding method, in particular, a print including a wiring made of copper or a copper alloy A fourth object is to provide a method for manufacturing a wiring board.

[0018]

Means for Solving the Problems The inventors of the present invention provide a copper etching solution with properties as a chemical polishing solution,
The present inventors have found that copper chloride deposition on the surface of the workpiece can be suppressed while maintaining the etching rate and the etching uniformity.

In order to achieve the first object, according to the present invention, an oxidizing agent and a coordinating compound (that is, monovalent or divalent) are used.
And a solution for copper or a copper alloy (hereinafter simply referred to as a copper solution) containing a compound that coordinates with a multivalent copper ion), and a method for producing the same. The copper solution of the present invention has both the properties as an etchant for copper (including its alloys; the same applies hereinafter) and the properties as a chemical polishing solution, and the processing conditions (time, temperature, concentration, etc.) Can be properly used as an etching solution or a chemical polishing solution.

The coordinating compound in the copper solution of the present invention has a function of reacting with copper ions eluted from the surface of the workpiece to form a complex having high solubility in water. In the present invention, since the coordinating compound is included as a component of the solution, copper ions eluted from the workpiece, instead of reacting with chloride ions to produce low-soluble copper chloride,
A complex with high solubility in water is formed, so that copper chloride does not deposit on the surface of the workpiece. Experiments performed by the inventor have shown that this complex formation reaction is accelerated by the presence of chloride ions under acidic conditions, and copper elution is correspondingly accelerated. This may be because copper complex ions are more thermodynamically stable than hydrated copper ions.

Since the copper solution of the present invention contains the above-mentioned coordinating compound, it has high resistance to chlorine contamination. Therefore,
Hydrogen peroxide or peroxodisulfate can be used as the oxidizing agent. When hydrogen peroxide is used as the oxidizing agent, a mineral acid is further used. By using such an oxidizing agent having excellent properties in safety and environmental hygiene, the copper solution of the present invention is easy to manage, has high safety, and is used as a preferable chemical polishing liquid in terms of environmental hygiene. be able to.

Further, the present inventors have found that chloride ions promote uniform dissolution of the surface of the workpiece because the migration speed in the aqueous solution is high. As described above, since the copper solution of the present invention has high resistance to chloride ions, chloride can be further contained as a supply source of chloride ions in order to improve the uniformity of dissolution.

In the present invention, the addition of chloride improves etching uniformity, bath life, bath stability, and the like, and the addition of a coordinating compound causes the deposition of copper chloride on the surface of the workpiece. Use of hydrogen peroxide and peroxodisulfate as oxidizing agents, which are highly safe and environmentally friendly because they are suppressed, and are used as a practical etching solution with excellent etching uniformity and bath stability Can be.

Further, in the present invention, in order to achieve the fourth object, a chemical polishing method and an etching method using the above-mentioned copper solution, and an etching process and / or a chemical polishing process using the method are performed. There is provided a method for manufacturing a copper molded body or a structure including the same (particularly, a printed wiring board), which includes a step of performing.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the concentration of a coordinating compound is adjusted so that the molar ratio to an oxidizing agent (hereinafter referred to as a relative molar concentration ratio) is in the range of 0.001% to 3%. It is preferable to use the compound in a relative molar concentration ratio of 0.03 to
It is particularly preferred to be 1.5%. When the relative molar concentration ratio is less than 0.001%, the resistance to chlorine contamination is not sufficient, and the action as a solution may be reduced. Further, when the relative molar concentration ratio is 3% or more, waste liquid treatment becomes difficult.

The concentration of the oxidizing agent in the copper solution of the present invention depends on the oxidizing power, but is generally preferably 0.2 to 1.5 mol / L in order to obtain a safe and practical processing speed. .

When peroxodisulfate is used as the oxidizing agent, the peroxodisulfate ion reacts slowly with water to generate sulfuric acid.
It is stable in the range of 0. For this reason, the dissolving solution of the present invention does not usually require any special pH adjustment work. However, if necessary, a small amount of sulfuric acid or the like may be added or a buffer component may be included. Further, for stabilizing the bath, known and commonly used additives such as alcohols and surfactants, stabilizers and the like may be included.

When hydrogen peroxide is used as the oxidizing agent, p-type hydrogen is added in advance so as not to be alkaline.
It is desirable to add a mineral acid in such an amount that H becomes 0.3 to 5.0. This is because within such a pH range, it is considered that the same basic characteristics regarding copper solubility as in the case of using the above-described peroxodisulfate are obtained. Examples of the mineral acid that can be used here include sulfuric acid, phosphoric acid, hydrochloric acid, perchloric acid, formic acid, and borofluoric acid.

Since it is difficult to completely eliminate the chlorine introduced from the outside during the process, it is not always easy to control the chloride concentration to less than 0.1 mol / L. No need. Further, even if chloride is added in excess of 2.0 mol / L, it is not consumed because it is consumed wastefully. Therefore, the range of the chloride concentration in the solution of the present invention is usually 0.1 to 2.0 mol.
/ L, preferably 0.3 to 1.2 mol / L. The use of a halide other than chloride, such as bromide, does not cause any serious problem in the properties as a solution, but chloride is most preferable in consideration of its price, availability, purity, stability and the like.

The coordinating compound used in the present invention comprises 1
It is desirable that the compound has a common logarithm of the complex formation constant K for the divalent or divalent copper ion in the range of 5.0 to 22.0, and the most preferable range of the complex formation constant is 8.0. １４14.5. When the common logarithm of the complex formation constant is less than 5.0, the resistance to chlorine contamination may not be sufficient. On the contrary, when it exceeds 22.0, the adsorption to the copper surface is so strong that the post-treatment is troublesome. become.

An example of a desirable molecular skeleton of the coordinating compound used in the present invention is a heteroaromatic nucleus. In a compound having a heteroaromatic nucleus (hereinafter, referred to as a heteroaromatic compound), in addition to the coordination of n-electrons on the heteroatom with copper ions, an adsorption effect of the aromatic nuclei on the metal copper surface by π electrons can be expected. Therefore, the common logarithm of the complex formation constant with copper may not necessarily be included in the above-mentioned desirable range of 5.0 to 22.0. Heteroaromatic compounds suitably used in the present invention include pyridine, bipyridyl, phenanthroline and derivatives thereof, and in addition, indole derivatives and quinoline derivatives. Examples of the derivatives of pyridine, bipyridyl, and phenanthroline include compounds having any one of the skeletons represented by the following chemical formula group (Formula 1).

[0032]

Embedded image

Although bipyridyl and phenanthroline have several isomers depending on the position of the nitrogen atom, 2,2'-bipyridyl and 1,10-phenanthroline or derivatives thereof form chelates with copper ions. The formation of a stable complex is particularly preferable.

Other coordinating compounds suitably used in the present invention include coordinating compounds having a bidentate or more and a hexadentate or less. In the case of a compound having a bidentate coordination site, at least one of the bidentate coordination atoms is preferably a nitrogen atom. Specific examples of such compounds include tartaric acid, malic acid, glycerol, erythritol, triethanolamine, ethylenediamine, diethylenetriamine, iminodiacetic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid, cyclohexanediaminetetraacetic acid, and aminobutyro. Nitrile and the like. Further, amino acids such as glycine, phenylalanine, valine, and tryptophan are also suitable coordination compounds for the present invention. In addition, the amino acid referred to in this specification refers to an amino acid in a broad sense including aminoalkylsulfonic acids such as taurine in addition to aminocarboxylic acids which are so-called amino acids in a narrow sense.

The copper solution of the present invention can be reused by regenerating the used solution. That is, the copper dissolving solution of the present invention is obtained by using an electrodialysis technique to remove unnecessary metal salts (copper ions, sulfate ions and chlorides) from a used dissolving solution having a reduced dissolving ability by etching or chemical polishing. (Ion), and can be produced by appropriately adding an oxidizing agent, a chloride and the like to the obtained aqueous solution containing a coordinating compound.

In the electrodialysis, as shown in FIG. 5, an anion exchange resin membrane 20 and a cation exchange resin membrane 2 are alternately arranged between an anode 17 and a cathode 18 connected to a DC power supply 16.
1 is placed in an electrodialysis cell 22 in which an electrode 17 and 1 are placed.
This is carried out by applying a DC voltage between 8. The dialysis membranes 20 and 21 used for electrodialysis are not particularly limited, and known and commonly used dialysis membranes can be used. For example, the dialysis membranes can be appropriately selected from an ion exchange membrane Selemion (registered trademark) series manufactured by Asahi Glass Co., Ltd. The dialysis conditions are appropriately determined according to the concentration, processing temperature, and the like so that divalent ions (copper ions and sulfate ions) and monovalent ions (chloride ions) and a coordinating compound can be efficiently separated. It is desirable to decide. In addition, in addition to this electrodialysis technique, a commonly known chemical or electrochemical oxidation-reduction reaction may be used in combination, or the coordination compound may be recovered and used alone.

The copper solution of the present invention can be easily regenerated as described above. By using this method for producing a copper solution by regeneration, the amount of waste liquid generated in etching and chemical polishing can be reduced, and chloride ions and coordinating compounds can be efficiently recovered and reused. Therefore, the solution can be produced at low cost.

The solution of the present invention can be used as a liquid having the same composition for both etching and chemical polishing by appropriately selecting the processing conditions (time, temperature, etc.). This compatibility is based on the size and shape of the copper or copper alloy to be processed,
It is not limited to its use or its molding / manufacturing process, but when forming a copper substrate into a fine pattern, the advantage is remarkably exhibited. In such a manufacturing process, for example, a resist is formed on a copper base material to be processed, then a resist pattern is formed, and the copper base material is selectively etched on the pattern using the resist pattern. There is a series of processes of stripping the resist and further brazing as necessary, and the etching method, the chemical method, and the method of forming a molded body using the solution of the present invention may be performed at any stage of such a process. Particularly suitable for application. For example, (1) surface treatment of base copper before resist film formation (2) pattern formation by selective etching of copper using a resist pattern (3) copper surface treatment after etching resist stripping (4) before brazing It is desirable to use the lysis solution of the invention in any one or more steps of the treatment.

In the above-described series of processes, the surface of the copper base material may be subjected to a surface roughening treatment before the formation of the resist in order to improve the adhesiveness of the resist. Especially for molding of fine shapes
At the time of processing, since the resist pattern has a small contact area with the base material, the resist is easily peeled off during processing, so such surface roughening treatment is indispensable for improving product quality and yield. is there. The copper solution of the present invention is suitable for chemical polishing roughening (soft etching) treatment on the surface of the substrate, and a fine rough surface state can be obtained by using the copper solution of the present invention. Resist adhesion is improved, which is effective in improving yield.

The dissolution solution of the present invention can be used as an etching solution for selective etching of a substrate after forming a resist pattern, if the processing conditions are changed.

Further, in the above-described process, when the resist is stripped after the pattern is formed by selective etching of the base material, a resist fragment may remain on the copper pattern. It is desirable to do. In this case, in particular, a molded body in which a fine pattern and a coarse pattern coexist is likely to cause uneven polishing and pattern deformation when mechanically polished. Therefore, chemical polishing is more preferable. The copper solution of the present invention can also be used as a bright polishing liquid, and is most desirable as a chemical polishing treatment liquid after resist removal.

When the copper or copper alloy solution of the present invention is used as an etching agent, the concentration of oxide is 0.7 to 1.5 mol / L and the concentration of chloride is 0.3 to 1.5 mol / L.
It is desirable that the concentration of the coordinating compound be 2.0 mol / L and the concentration of the oxidizing agent be 0.01 to 3.0 mol%. The etching process using this solution is performed, for example, at a solution temperature of 35 to
It is desirable to carry out the process by spraying a solution at 80 ° C. on the portion to be etched.

When the copper or copper alloy solution of the present invention is used as a surface roughening agent, the concentration of the oxide is set to 0.1.
2 to 1.2 mol / L, chloride concentration 0.1 to 0.7
mol / L, the concentration of the coordinating compound is 0.01% of the oxidizing agent.
It is desirable to set it to 1.5 mol%. The surface roughening treatment using this solution is performed, for example, by subjecting the treatment target to 15 ° C.
It can be carried out by immersing in the following solution and standing (within 30 seconds).

When the solution for copper or copper alloy of the present invention is used as a bright abrasive, the concentration of the oxide is 0.2 to 0.2.
1.2mol / L, chloride concentration 0.3-1.5mo
1 / L, the concentration of the coordinating compound is 0.01 to
It is desirable to set to 1.5 mol%. The bright polishing treatment using this solution is performed, for example, by finely spraying a solution at 20 to 30 ° C. onto the object to be treated and then washing with dilute sulfuric acid, or adding a solution to the solution at 5 to 20 ° C. Dipping
After the rocking (within 1 minute), washing can be performed by dilute sulfuric acid.

The copper compact obtained in this manner may be used as it is as a final product, or may be used by additionally processing it. Examples of additional processes suitable for the present invention include brazing, nickel plating, copper plating, and chemical vapor deposition (CVD). In the case of brazing (soldering) or plating, a problem is likely to occur if an oxide film is present on the surface or if dirt is attached. Therefore, it is desirable to brightly polish the surface as a pretreatment, and the copper solution of the present invention can also be used in this bright surface polishing step. By inserting the surface bright polishing step using the copper solution of the present invention between the molding step and the additional processing step, the bonding strength of soldering is increased, or high quality plating without voids and nodules The surface is obtained.

As described above, the copper solution of the present invention can be used in all of the above steps (1) to (4). Therefore, by using the copper solution of the present invention, the processing which has been conventionally performed by combining the etching solution and the mechanical polishing equipment can be unified into one type of solution. As a result, the number of types of processing solutions to be managed is reduced, the number of baths for processing solutions is reduced,
Achieving batch treatment of waste liquid, it is possible to reduce the processing and manufacturing costs of copper compacts. In particular, it is effective to use the copper solution of the present invention in the etching step and the chemical polishing step of all copper members.

If the solution of the present invention contains an additive (such as an abrasive) having a mechanical polishing action, it can be used as a solution for chemical mechanical polishing. It may be used in a pretreatment stage such as plating or CVD.

The forming method of the present invention can be applied to the formation of any material as long as it is made of copper or a copper alloy. Suitable for forming. In particular, when the pattern is a wiring pattern of an electric / electronic circuit, the features of the present invention are more than fully exhibited, and the production quality and production efficiency of a printed circuit board, a ceramic substrate, a semiconductor, and the like made of the pattern are improved. Enable.

[0049]

EXAMPLES The features of the present invention will be described below with reference to examples, but the present invention is not limited to the use conditions in these examples.

Example 1 200 g of disodium peroxodisulfate as an oxidizing agent, 30 g of ammonium chloride as a chloride, and 0.1 ml of pyridine which is a heteroaromatic compound as a coordinating compound were weighed out and purified with pure water. It was dissolved in 1 liter to obtain a copper solution. After completely dissolving all the components, the pH was measured to be about 3.0. The common logarithm of the complex formation constant (total stability constant) of pyridine with respect to monovalent copper ion is 8.5.

This copper solution was filled in a tank and kept at a temperature of 15 ° C. or lower, into which 30 cm × 30 cm shown in FIG.
When the substrate 2 on which the copper foil 1 (thickness: 35 μm) having a size of 50 cm was stuck was immersed for 10 seconds, the surface of the copper foil 1 was micro-etched, and the copper metal crystal was etched.
figure) appeared, and a uniform rough surface 3 was formed over the entire surface of the substrate (FIG. 1B).

Next, a dry film resist (“Fotech (registered trademark) H-K350”, manufactured by Hitachi Chemical Co., Ltd.) (photosensitive main wavelength: 36) is formed on the copper foil 1 whose surface is roughened.
5 nm)) and “HMW-201” manufactured by Oak Co., Ltd.
Exposure was performed through an arbitrary mask pattern using a “B-type exposure machine” (output: 3 KW), and developed with a 1% by weight aqueous solution of sodium carbonate to form a resist film 4 having a predetermined pattern (FIG. 1C). .

The copper foil 1 heated at 50 ° C. was sprayed onto the substrate to spray-etch, and the copper foil 1 was pattern-etched and sufficiently washed with water. Then, the resist film 4 was washed with a 3% by weight aqueous sodium hydroxide solution. When peeled, no chipping of the copper pattern was observed. At this point, the surface of the obtained copper pattern 5 has been roughened due to the surface dissolution treatment performed in the pretreatment for resist film formation (FIG. 1).
(D)).

Then, the above copper solution maintained at 25 ° C. was sprayed on the pattern surface in a fine mist state and further washed with dilute sulfuric acid. As a result, the patterned copper foil 1 was polished brightly.
The surface became glossy. Next, electroless copper plating was performed on the obtained surface glossy copper pattern 5 to form a copper pattern 6 having a thickness of 50 μm. No precipitate, nodules, voids, and the like were found in the obtained copper molded body 6 having a predetermined pattern (FIG. 1E).

Example 2 In this example, bipyridine which is a heteroaromatic compound was used as the coordinating compound.
That is, in this example, a copper solution was prepared in the same manner as in Example 1, except that a 10% by weight ethanol solution of bipyridine was used instead of pyridine, and the concentration of bipyridine in the copper solution was 30 mg / L. did. The pH was measured to be about 1.5 after all components were completely dissolved. Since bipyridyl is a crystalline substance and has a low dissolution rate in water, in this example, the bathing time was reduced by adding it as an ethanol solution. The common logarithm of the complex formation constant (total stability constant) of bipyridyl with respect to monovalent copper ion is 14.4.

Except that this copper solution was used for surface roughening, pattern etching and bright polishing,
Pretreatment (roughening), resist lamination, exposure, development, pattern etching, and bright polishing were performed on the same copper foil-clad substrate as in Example 1. However, in this embodiment, the polished surface was immersed in a copper solution tank kept at 15 ° C. without spraying in a fine mist state as in Embodiment 1 during the bright polishing, and the diluted sulfuric acid cleaning and high pressure Spray washing was performed. Also in this embodiment, the first embodiment
As a result, a bright copper pattern 5 of the same quality as that obtained was obtained. Finally, after electroless nickel plating (plating thickness 10 μm) was performed on the surface of the copper pattern 5 and an appearance inspection was performed, no undeposited portions, nodules, voids, or chipping of the pattern were detected at all.

Example 3 In this example, glycine, which is an amino acid, was used as a coordinating compound, and its concentration was 1 g.
A copper solution was prepared in the same manner as in Example 1 except that / L was used. After completely dissolving all components, the pH was measured to be about 2.0. The common logarithm of the complexation constant of glycine for divalent copper ions is 15.4.

In this embodiment, a copper-clad laminate (manufactured by Hitachi Chemical Co., Ltd.) was used instead of the copper foil-clad board used in the first embodiment.
Using a copper-clad laminate “MCL (registered trademark) -F-67” (copper foil thickness: 35 μm) for a multilayer printed wiring board, the same treatment as in Example 1 was performed. However, the above-mentioned glycine-containing copper solution was used for roughening, pattern etching and bright polishing. After electroless copper plating in the final stage, pattern inspection was performed on the printed wiring board with copper wiring 6 formed on the surface, and no undeposited spots, nodules, voids, or chipped patterns were detected at all. Was not done.

Further, in the present embodiment, electronic components were mounted and mounted on the surface of the printed wiring board in accordance with a predetermined soldering process to produce an electronic circuit device. In this device, the copper pattern 6 formed according to the present embodiment is used as a signal wiring. When the operation of this device was confirmed, no malfunction of the circuit was observed at all.

Example 4 In this example, a copper solution was prepared using aqueous hydrogen peroxide as an oxidizing agent. That is,
100 ml of 30% by weight hydrogen peroxide solution and 20 g of concentrated sulfuric acid
And ammonium chloride 30 g and pyridine 0.1 ml
Was added to pure water to make the total amount 1 liter. The concentration of hydrogen peroxide in the obtained copper solution is 3% by weight, and the concentration of sulfuric acid is about 2% by weight. After completely dissolving all components, the pH was measured to be about 0.4.

Except that this copper solution was used for surface roughening, pattern etching and bright polishing,
When the same copper foil-clad board as in Example 3 was processed, and a pattern inspection was performed on the board subjected to electroless copper plating in the final stage, no undeposited portions, nodules, voids, or chipping of the pattern were found. Not detected. Furthermore, using the obtained substrate with a copper pattern, an electronic circuit device using a copper pattern as a signal wiring was produced in the same manner as in Example 3, and no operation failure of the circuit was observed.

Example 5 The spent copper solution (100 ml each) used in Examples 1 and 4 was mixed and subjected to an electrodialysis treatment. In this example, ten sheets of Selemion (registered trademark) CMV manufactured by Asahi Glass Co., Ltd. were used as the cation exchange resin membrane, and one part of Selemion (registered trademark) AMP manufactured by Asahi Glass Co., Ltd. was used as the anion exchange resin membrane.
Using a single electrodialysis layer, a voltage of 10 V was applied between both electrodes for 12 hours. As a result, most of the copper sulfate (sulfate ion and copper ion) dissolved in the used copper solution was removed.

The used copper dissolving solution from which the copper sulfate was almost removed was mixed with the copper dissolving solution of Example 4 so as to have a concentration similar to that of the copper dissolving solution of Example 4.
% By weight aqueous hydrogen peroxide, concentrated sulfuric acid, ammonium chloride and pyridine were added. The obtained regenerating solution is used as a copper solution for surface roughening, pattern etching and bright polishing,
When the same processing of the copper foil-clad substrate as in Example 1 was performed, no deposits, nodules, voids, or chipped patterns were not detected at all in the pattern inspection after the electroless plating.

<Comparative Example 1> In this comparative example, the same copper foil-clad board as in Example 1 was subjected to surface roughening treatment without being subjected to surface roughening treatment.
A resist pattern 4 was produced by sequentially performing the same resist lamination, exposure and development as in Example 1. The processing apparatus, processing conditions, processing solution, and film resist used during this period were exactly the same as in Example 1.

Next, the pattern etching of the copper foil 1 was carried out by using an ammonia-based etching solution ("Al process (registered trademark)" manufactured by Meltec Co.) for the pattern etching. The resist was stripped using a 3% by weight aqueous sodium hydroxide solution.

When the shape of the formed pattern was examined, a large number of pattern formation defects were found due to scratches, dents, and stains on the copper foil when the substrate was manufactured. In the case of a fine pattern having a line width of 100 μm or less, the pattern line width was insufficient or the pattern was missing. This is considered to be because the surface roughening treatment of the copper foil 1 was not performed before the resist lamination, so that the adhesiveness of the resist was insufficient, and the resist pattern edge was lifted during the development of the resist pattern. Further, even in the case of a pattern having a line width of 150 μm or more, there were some places where the etching liquid permeated from the gaps at the resist end portions and the pattern was discolored. Such discoloration significantly impairs the appearance,
Further, the efficiency of pattern inspection is reduced.

When the copper pattern 5 was subjected to electroless copper plating without polishing the surface,
Many undeposited portions, nodules, and voids were generated at the discolored portions described above.

<Comparative Example 2> In this comparative example, a mechanical polishing step was inserted in the step of Comparative Example 1. First, the surface of the copper foil 1 of the copper foil-clad board similar to that in Example 1 was buffed to remove scratches, dents, and stains. Thereafter, as in Example 1, resist lamination, exposure, and development were sequentially performed to form a resist pattern. The processing apparatus, processing conditions, processing solution, and film resist used during this period were exactly the same as in Example 1.

Next, as in Comparative Example 1, pattern etching was performed using an ammonia-based etching solution.
When the shape of the pattern 5 was examined after the resist was peeled off, no pattern formation defect derived from scratches, dents, and dirt was found. However, the rough surface obtained by the buff polishing is inferior in roughness to the rough surface obtained by the chemical polishing in Example 1, so that the adhesion of the resist is still insufficient, and the fine pattern having a line width of 80 μm or less is still insufficient. In this case, the pattern line width was insufficient and the pattern was missing. Also, line width 1
The occurrence of discoloration in the pattern of 50 μm or more did not become zero.

When the surface of the obtained pattern 5 was buff-polished, the appearance was improved, the efficiency of pattern inspection was improved, and the number of defective plating was reduced.
There was a portion where peeling occurred in a fine pattern of 00 μm or less.

[0071]

According to the present embodiment, a copper solution having the same composition can be used for both the etching step and the chemical polishing step. By using the copper solution of the present invention, the processing liquid for etching and chemical polishing can be unified, so that it is possible to reduce the number of types of processing liquid, reduce the number of baths of processing liquid, and collectively treat waste liquid. It is possible to improve the production quality and production efficiency when the obtained pattern is additionally processed.

Further, in the present invention, a peroxodisulfate or hydrogen peroxide can be used as an oxidizing agent, so that a practical copper dissolving solution having high safety, easy handling in environmental hygiene, low cost and low cost is provided. Is done. Furthermore, since the copper solution of the present invention has a high chloride ion resistance, it has a long bath life and a high bath stability.In addition, even when chloride is added, there is no deposition of copper chloride. Can improve the etching uniformity.

Further, according to the present invention, by regenerating the above-mentioned copper solution, the copper solution can be produced at low cost and resources can be saved.

Further, according to the present invention, by using the above-mentioned copper solution, it is possible to avoid the problem of the resist peeling step in the processing and manufacturing method of the copper molded body using the etching resist. By using the solution for both chemical polishing and etching, a copper structure (particularly a printed wiring board) can be processed and manufactured at low cost and high efficiency.

Further, in the present invention, in the etching process of the copper base material, the pre-treatment of the resist film formation, the pattern etching,
In at least one of the steps of polishing after removing the resist, a surface treatment of the copper base material is performed. This improves the adhesion of the resist, reduces pattern etching defects,
The appearance can be improved, the inspection efficiency can be improved, or defects can be reduced in later steps.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a step of forming a patterned copper compact in Example 1.

FIG. 2 is an explanatory view showing the concept of chemical polishing.

FIG. 3 is an explanatory diagram showing the concept of etching.

FIG. 4 is an explanatory view showing a forming process of a copper compact having both an etching step and a chemical polishing step.

FIG. 5 is a schematic diagram showing a method of regenerating a used copper solution using electrodialysis.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Copper foil, 2 ... Substrate, 3 ... Roughened surface, 4 ... Patterned resist film, 5 ... Copper foil etched in a pattern, 6 ... Copper pattern after copper plating, 7 ... Copper substrate surface 8: Unevenness of copper substrate surface, 9: Copper substrate, 10 ...
Chemically polished copper base material, 11: etching resist, 12: etched copper base material, 14: surface roughened copper base material, 15: groove formed by etching, 16: DC power supply, 17 ... Anode, 18 ... Cathode, 19 ...
Used solution, 20: anion exchange resin membrane, 21: cation exchange resin membrane, 22: electrodialysis electrolytic cell.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshinori Muramatsu 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture In the Information and Communication Division of Hitachi, Ltd.

Claims (18)

[Claims] 1. A solution for copper or a copper alloy, which is an aqueous solution containing an oxidizing agent and a coordinating compound that is a compound that coordinates to monovalent and / or divalent copper ions. 2. The solution for copper or copper alloy according to claim 1, wherein said aqueous solution further contains chloride. 3. The solution according to claim 1, wherein the concentration of the oxidizing agent is 0.2 to 1.5 mol / L, and the concentration of the chloride is 0.1 to 2.0 mol / L. Wherein the molar ratio of the oxidizing agent to the coordinating compound is 100:
A solution for copper or a copper alloy, which is 0.001 to 100: 3. 4. The solution for copper or copper alloy according to claim 1, wherein the oxidizing agent is a peroxodisulfate. 5. The solution for copper or copper alloy according to claim 1, wherein the oxidizing agent is hydrogen peroxide, and the aqueous solution further contains a mineral acid. . 6. The solution according to claim 1 or 2, wherein the coordinating compound has a common logarithm of a complex formation constant for monovalent or divalent copper ions of 5.0 or more and 22.0 or less. Dissolving solution for copper or copper alloy characterized by the following. 7. The solution for copper or copper alloy according to claim 1, wherein at least one of the coordinating compounds is a heteroaromatic compound. 8. The solution according to claim 7, wherein at least one of the coordinating compounds has at least one of the skeletons represented by the following chemical formula group (Formula 1). Solution for copper or copper alloy. Embedded image 9. The solution according to claim 1, wherein at least one of the coordinating compounds is a compound having a bidentate or more and 6 or less coordination sites with respect to a copper ion. Characterized solution for copper or copper alloy. 10. The solution according to claim 9, wherein at least one of the coordinating compounds is a compound having a bidentate coordination site with respect to a copper ion. A solution for copper or a copper alloy, wherein at least one coordination atom is a nitrogen atom. 11. The solution according to claim 10, wherein the compound having a bidentate coordination site with respect to the copper ion is:
A solution for copper or copper alloy, which is an amino acid. 12. A process for regenerating a lysate by removing copper ions by electrodialysis from a used lysate obtained by using the lysate according to claim 1 or 2 for copper dissolution treatment. The method for producing a solution for copper or copper alloy according to claim 1, wherein: 13. An etching method for dissolving and removing at least a part of a substrate made of copper or a copper alloy using a dissolving solution, wherein the dissolving solution comprises an oxidizing agent and monovalent and / or divalent copper ions. An etching method, which is an aqueous solution containing a coordinating compound that is a compound that is coordinated with a metal. 14. The surface of a substrate made of copper or a copper alloy,
In the chemical polishing method for polishing using a solution, the solution is an aqueous solution containing an oxidizing agent and a coordinating compound that is a compound that coordinates to monovalent and / or divalent copper ions. Characteristic chemical polishing method. 15. A method for forming a copper or copper alloy compact, comprising the step of polishing the surface of a copper or copper alloy compact using the chemical polishing method according to claim 14. 16. A molded body made of copper or copper alloy, comprising a step of forming an etching resist having a predetermined pattern on a base material made of copper or copper alloy, etching the base material, and removing the etching resist. The method for forming a molded article according to claim 1, further comprising a step of polishing the surface of the base material after the etching resist is removed. 17. The method according to claim 16, wherein the polishing step is performed by the chemical polishing method according to claim 14. 18. A method for manufacturing a printed wiring board, comprising a step of forming a wiring made of copper or a copper alloy using the forming method according to claim 15.