JP2001181867A - Microetching agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microetching agent usable for approximately all etching tanks including stainless tanks and also capable of executing good microetching without generating unevenness in etching even in the case microstains such as oily components are present on the surface of copper. SOLUTION: This microetching agent for copper and/or copper alloys is composed of an aqueous solution containing (a) ferric sulfate (III), (b) sulfuric acid and (c) a nonionic surfactant, the concentration of (a) is 1 to 40 wt.%, the ratio of (b) to 100 pts.wt. of (a) is 5 to 50 pts.wt., the concentration of (c) is 0.01 to 10 wt.%, the content of halogen is <0.01 wt.%, and, suitably, (d) phosphoric acid of 0.01 to 30 wt.%, or carboxylic acid of 0.01 to 30 wt.%, or phosphoric acid of 0.01 to 15 wt.% and carboxylic acid of 0.01 to 15 wt.% are contained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microetching agent suitable for surface treatment of copper and / or copper alloy.

[0002]

2. Description of the Related Art In the manufacture of printed wiring boards and the like,
Circuits are formed by forming an etching resist or a solder resist on the surface of a layer made of copper or a copper alloy (hereinafter collectively referred to as a copper surface). At this time, in order to form the etching resist and the solder resist satisfactorily, the copper surface is etched by about 0.1 to 5 μm by micro-etching (chemical polishing) to clean, roughen or activate the copper surface. That is being done. As a microetching agent for a copper surface, an etching agent mainly containing sulfuric acid and hydrogen peroxide has been mainly used. In recent years, an automatic system that can be used continuously using an etching agent based on iron (III) chloride or iron (III) sulfate to avoid excessive etching has also been used for improving productivity.

[0003]

As such a micro-etching agent for the copper surface, there is a micro-etching agent described in JP-A-9-41162. However, this microetching agent contains a halogen component as an active ingredient, and when used in a microetching system using a stainless steel tank, the stainless steel tank is attacked,
It could not be used for such a system.
In addition, this microetching agent causes uneven etching when fine dirt such as an oil component is present on the copper surface. Therefore, an object of the present invention is to provide a good micro-etching that can be used for most etching tanks including a stainless steel tank and that does not cause uneven etching even when minute stains such as oily components are present on the copper surface. An object of the present invention is to provide a microetching agent that can be used.

[0004]

That is, the present invention provides (a)
A microetching agent for copper and / or copper alloy, comprising an aqueous solution containing iron (III) sulfate, (b) sulfuric acid, and (c) a nonionic surfactant, wherein the concentration of (a) is 1
(B) is 5 to 50 parts by weight with respect to 100 parts by weight of (a), the concentration of (c) is 0.01 to 10% by weight, and the halogen content is 0 to 40% by weight. .01
A micro-etching agent that is less than wt%,
The present invention further provides (d) 0.01 to 30% by weight of phosphoric acid, or (e) 0.01 to 30% by weight of carboxylic acid, or (d) 0.01 to 15% by weight of phosphoric acid and (e) A microetching agent containing 0.01 to 15% by weight of carboxylic acid.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The microetchant of the present invention comprises (a) iron (III) sulfate and (b) sulfuric acid, and (a) 1
(B) is contained in an amount of 5 to 50 parts by weight, preferably 10 to 35 parts by weight, based on 00 parts by weight.
If the ratio of (b) is less than the above amount, etching unevenness occurs, and depending on the amount of iron or copper dissolved, these hydroxides may precipitate. When a precipitate is generated, particularly in a continuously automated system, a problem such as clogging of a pipe for supplying an etching solution occurs. Also, when the ratio of (b) exceeds the above amount, etching unevenness occurs, and a precipitate of copper sulfate may be generated depending on the amount of iron or copper dissolved. The amount of (a) and (b) used in the microetching agent of the present invention is exemplified by the amount of (a) because the ratio of both is as described above.
It is preferable to use the microetchant in a concentration range of 1 to 40% by weight, preferably 10 to 25% by weight.
If the amount of (a) is less than the above amount, the etching speed becomes too slow and the industrial practicality is lowered. If the amount exceeds (a), uneven etching occurs.

The microetchant of the present invention comprises (c)
It contains a nonionic surfactant in a concentration of 0.01 to 10% by weight, preferably 0.1 to 5% by weight. If the concentration of (c) is less than the above, if dirt, dust, etc. such as oily substances adhere to the copper surface, they remain on the copper surface and the wettability is not sufficient, resulting in uneven etching. Also,
If the concentration of (c) exceeds the above, the nonionic surfactant itself remains on the copper surface, and the copper surface is liable to discolor. The nonionic surfactant (c) used in the present invention is not particularly limited, and any nonionic surfactant can be used, for example, an ester type nonionic surfactant and its alkylene oxide. Non-ionics such as adducts, amide type nonionic surfactants and alkylene oxide adducts thereof, alkylene oxide adducts of fatty acids, alkylene oxide adducts of alcohols, alkylene oxide adducts of amines, and polyalkylene oxides A non-ionic surfactant can be exemplified.

[0007] The ester type nonionic surfactant is an ester of a fatty acid, and the fatty acid has 8 carbon atoms.
To 24, preferably 12 to 20, saturated or unsaturated fatty acids, which may be linear or branched, and may have a substituent containing an aromatic group and / or an alicyclic group. The alcohol constituting the ester is a polyhydric alcohol, for example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, diglycerin, triglycerin, polyglycerin, sorbitan, sorbitol, trimethylolpropane, pentaerythritol, Pentaerythritol, sucrose and the like can be mentioned. The esters of these fatty acids and polyhydric alcohols may be monoesters, diesters, or polyesters as long as the hydroxyl groups remain. A compound in which an alkylene oxide has been added to the hydroxyl group of the ester-type nonionic surfactant can also be used. As the alkylene oxide, ethylene oxide, propylene oxide, butylene oxide, or the like can be used alone or in combination of two or more (random or block), but it is preferable to use ethylene oxide at least in part.

The amide type nonionic surfactant is an amide of a fatty acid, and the fatty acid has 8 to 2 carbon atoms.
4, preferably 12 to 20 saturated or unsaturated fatty acids, which may be linear or branched, and may have a substituent containing an aromatic group and / or an alicyclic group.
The amine constituting the amide is an alkanolamine, for example, ethanolamine, propanolamine,
Examples thereof include butanolamine, diethanolamine, dipropanolamine, dibutanolamine, and triethanolamine. A compound in which an alkylene oxide is added to a hydroxyl group of the amide-type nonionic surfactant can also be used. As the alkylene oxide, ethylene oxide, propylene oxide,
Although butylene oxide or the like can be used alone or in combination of two or more (random or block-like), it is preferable to use ethylene oxide at least in part.

The fatty acid constituting the alkylene oxide adduct of the above fatty acid is a saturated or unsaturated fatty acid having 8 to 24, preferably 12 to 20 carbon atoms, which may be linear or branched, and having an aromatic group. And / or a substituent having an alicyclic group. As the alkylene oxide to be added to -OH of the carboxyl group of the fatty acid, ethylene oxide, propylene oxide, butylene oxide, or the like can be used alone or in combination of two or more (random or block-like). It is preferred to use.

The alcohol constituting the alkylene oxide adduct of the alcohol is a monohydric alcohol,
Either a polyhydric alcohol or a polyhydric alcohol may be used, and the monohydric alcohol is an aliphatic having a saturated or unsaturated linear or branched hydrocarbon group having 8 to 24, preferably 12 to 20 carbon atoms. Alcohols (which may have a substituent containing an aromatic group and / or an alicyclic group), aromatic alcohols having at least one aromatic group having 6 to 30 carbon atoms (alkyl substituents or aromatic Which may be substituted with an alkyl substituent having an aromatic group), which may be a primary alcohol or a secondary alcohol. As the dihydric alcohol, ethylene glycol, propylene glycol,
Alkylene glycols such as butylene glycol, aromatic dihydric alcohols such as bisphenol A and the like, and polyhydric alcohols include glycerin, diglycerin, triglycerin, polyglycerin, sorbitan, sorbitol, trimethylolpropane, pentaerythritol,
Dipentaerythritol, sucrose and the like. As the alkylene oxide to be added to —OH of the alcohol, ethylene oxide, propylene oxide, butylene oxide, or the like can be used alone or in combination of two or more (in random or block form). At least a part of ethylene oxide is used. Is preferred.

The amines constituting the alkylene oxide adduct of the above amines include polyalkylene polyamines such as ethylenediamine, diethylenetriamine and triethylenetetramine, and saturated or unsaturated straight-chain compounds having 8 to 24, preferably 12 to 20 carbon atoms. Aliphatic amine having a hydrocarbon group which may be linear or branched (may have a substituent containing an aromatic group and / or an alicyclic group), and at least one having 6 to 30 carbon atoms An aromatic amine having an aromatic group (which may be substituted with an alkyl substituent or an alkyl substituent having an aromatic group) may be mentioned. As the alkylene oxide to be added to -NH of the amine, ethylene is used. Oxide, propylene oxide, butylene oxide, etc., alone or in combination (random Shape or block shape) may be used, but it is preferable to use ethylene oxide at least in part.

The above-mentioned polyalkylene oxides are those obtained by polymerizing (randomly or blockwise) ethylene oxide, propylene oxide, butylene oxide or the like, at least in part. It is preferred to use an oxide.

As the nonionic surfactant (c) used in the present invention, a type to which ethylene oxide and propylene oxide are added is more preferable in view of the effect of the present invention.

Among the above (c) nonionic surfactants, when it is desired to particularly suppress foaming during use, a propylene oxide ethylene oxide random adduct of propylene glycol or a propylene oxide ethylene oxide adduct of a polyalkylene polyamine is used. (It may be random or block-like, but preferably block-like). It is particularly preferable to use propylene oxide-ethylene oxide random adduct of propylene glycol, more preferably propylene oxide:
It is preferred to use ethylene oxide having a molar ratio of 2: 8 to 4: 6 and a molecular weight of 500 to 2,000.

The microetching agent of the present invention includes
As component (d) phosphoric acid can be used in a concentration of 0.01 to 30% by weight, preferably 0.1 to 2% by weight. Generally, after micro-etching, post-processing such as cleaning is performed promptly, and the next patterning step is performed promptly. However, cleaning is not performed promptly or insufficiently, and up to the patterning step. If the microetching itself is good, a partial copper oxide thin film is gradually formed on the copper surface, which may cause unevenness in the patterning process. However, by containing (d) phosphoric acid, it is possible to prevent the formation of copper oxide (rust prevention) even when post-processing of microetching is not appropriate.
(D) If the amount of phosphoric acid is less than the above amount, the difference from the case where no phosphoric acid is used is not significant, and even if the amount exceeds the above amount, the effect is not further improved, and industrial suitability is rather impaired. It will be.

The microetching agent of the present invention includes:
As the fourth component, the above carboxylic acid (e) is used in an amount of 0.01 to 30.
%, Preferably at a concentration of 0.1 to 2% by weight. (E) The solubility of an organic substance is improved by containing a carboxylic acid, so that the effect of the above (c) nonionic surfactant can be further ensured. (E) If the amount of the carboxylic acid is less than the above amount, the difference from the case where no carboxylic acid is used is not significant, and if the amount exceeds the above amount, a precipitate may be generated. (E) The carboxylic acid is not particularly restricted but includes, for example, aliphatic saturated carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid and caproic acid, acrylic acid, methacrylic acid, crotonic acid, irocroton Aliphatic unsaturated carboxylic acids such as acids, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, aliphatic saturated dicarboxylic acids such as pimelic acid, maleic acid and other aliphatic unsaturated dicarboxylic acids, benzoic acid, phthalic acid Aromatic carboxylic acids such as acid and cinnamic acid, oxycarboxylic acids such as glycolic acid, lactic acid, malic acid, tartaric acid and citric acid, sulfamic acid, β-chloropropionic acid, nicotinic acid, ascorbic acid, hydroxypivalic acid and levulinic acid And the like, and derivatives thereof.

Further, the microetching agent of the present invention comprises:
The combination of (d) phosphoric acid and (e) carboxylic acid as the fourth and fifth components provides a more effective and preferable microetching agent. In this case, these (d) phosphoric acid,
(E) The range of the amount of each carboxylic acid used is (d) = 0.
01 to 15% by weight, (e) = 0.01 to 15% by weight, which can be set independently of each other. These (d)
The effects when the amounts of phosphoric acid and (e) carboxylic acid are out of the respective ranges are the same as described above.

The microetchant of the present invention has a halogen content of less than 0.01% by weight. When the halogen content is 0.01% by weight or more, when a stainless steel bath is used for microetching, the stainless steel bath is eroded, and conditions for use as a microetchant are limited. It lacks practicality.

[0019]

EXAMPLES The present invention will be further described with reference to examples, but the present invention is not limited to these examples. [Examples 1 to 36] [Comparative Examples 1 to 6] A microetching agent having the composition shown in Tables 1 to 6 was prepared, and this microetching agent was coated with a 50 mm thick copper foil layer having a thickness of 18 μm.
The surface of the copper-clad laminate of 50 mm was sprayed at a liquid temperature of 30 ° C. for 60 seconds and etched. The copper surface after etching was evaluated for the following items. The results are shown in Tables 1 to 6.
In Tables 1 to 6, the halogen content (chlorine ion concentration) is less than 0.005% by weight.

[Discoloration Resistance] The copper surface after etching was visually observed. The evaluation criteria are as follows. Evaluation criteria: ：: No discoloration was observed over the entire copper foil surface. ：: A slight discoloration was observed on a part of the copper foil surface, but there was no problem in practical use. Disturbance XX: Discoloration was observed over the entire copper foil surface, making it impractical. [Etching unevenness] The copper surface after etching was visually observed. The evaluation criteria are as follows. Evaluation Criteria: 全 く: No unevenness was observed over the entire copper foil surface. 微: A slight unevenness was observed on a part of the copper foil surface, but there was no problem in practical use. XX: Unevenness is observed over the entire copper foil surface, making it impractical. [Sample] (a): Iron (III) sulfate (b): Sulfuric acid (c) -1: Ethylenediamine ethylene oxide propylene oxide block adduct ( Molecular weight = 5000
/ EO content = 40% by weight) (c) -2: Polyoxyethylene polyoxypropylene random copolymer (molecular weight = 1000 / EO content = 70)
(C) -3: Ethylene glycol monostearate ethylene oxide adduct (EO addition = 8 mol) (c) -4: Diethanolamine monooleylamide ethylene oxide adduct (EO addition = 9 mol) (c) ) -5: Ethylene oxide adduct of stearic acid (EO addition = 8 mol) (c) -6: Ethylene oxide propylene oxide block adduct of lauryl alcohol (molecular weight = 200)
(C) -7: 2-octanol ethylene oxide propylene oxide block adduct (molecular weight = 2000 /
(EO content = 40% by weight) (c) -8: Ethylene oxide adduct of nonylphenol (EO addition amount = 9.5 mol) (c) -9: Ethylene oxide propylene oxide block adduct of ethylene glycol (molecular weight = 200)
0 / EO content = 40% by weight) (c) -10: Ethylene oxide adduct of sucrose (EO)
(C) -11: sucrose stearic acid ester (average degree of esterification 2) (c) -12: triethanolamine lauric amide (c) -13: propylene oxide ethylene oxide random addition of propylene glycol (Molecular weight = 7
(00 / PO: EO = 3: 7) (c) -14: Propylene glycol ethylene oxide random adduct of propylene glycol (molecular weight = 1)
000 / PO: EO = 3: 7) (c) -15: Propylene oxide ethylene oxide random adduct of propylene glycol (molecular weight = 1)
500 / PO: EO = 3: 7) (c) -16: Propylene oxide ethylene oxide random adduct of propylene glycol (molecular weight = 1)
000 / PO: EO = 2.5: 7.5) (c) -17: Propylene oxide ethylene oxide random adduct of propylene glycol (molecular weight = 1)
000 / PO: EO = 3.5: 6.5) (d): Phosphoric acid (e) -1: Formic acid (e) -2: Acetic acid (e) -3: Succinic acid (Note) EO content = 1 molecule Percentage of total oxyethylene groups in the mixture (Note) EO addition = styrene oxide addition per molecule

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

[0024]

[Table 4]

[0025]

[Table 5]

[0026]

[Table 6]

[Stainless Steel Corrosion Test] Stainless steel sheet SUS of 30 mm × 50 mm × 10 mm as a test piece
The −304 material was immersed in an etchant having the composition shown in Table 7 for 15 days or 30 days, and the corrosion state was evaluated by a gravimetric method. Table 7 shows the results.

[0028]

[Table 7]

[0029]

The effect of the present invention can be applied to most etching tanks including a stainless steel tank, and is excellent without causing uneven etching even when minute stains such as oily components are present on the copper surface. Another object of the present invention is to provide a microetching agent capable of performing microetching.
By performing microetching using the microetching agent of the present invention, a copper surface suitable for favorably forming an etching resist and a solder resist can be obtained.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ryoji Kabuya 7-35, Higashiogu, Arakawa-ku, Tokyo Asahi Denka Kako Kogyo Co., Ltd. (72) Inventor Yoshitsugu Ishizuka 7-2 Higashiogu, Arakawa-ku, Tokyo No. 35 Asahi Denka Kogyo Co., Ltd. (72) Inventor Kazutada Komura 7-35 Higashiogu, Arakawa-ku, Tokyo Asahi Denka Kogyo Co., Ltd. F-term (reference) 4K057 WA01 WA05 WA11 WB04 WE03 WE04 WE11 WE12 WE13 WE14 WE15 WE30 WG03 WN01

Claims (4)

[Claims] 1. A microetching agent for copper and / or copper alloy comprising an aqueous solution containing (a) iron (III) sulfate, (b) sulfuric acid and (c) a nonionic surfactant, The concentration of (a) is 1 to 40% by weight;
(B) is 5 to 50 parts by weight to 00 parts by weight, the concentration of (c) is 0.01 to 10% by weight, and the halogen content is less than 0.01% by weight. A microetching agent. (2) iron (III) sulfate, (b) sulfuric acid,
A microetching agent for copper and / or copper alloy, comprising an aqueous solution containing (c) a nonionic surfactant and (d) phosphoric acid, wherein the concentration of (a) is 1 to 40% by weight. (B) is 5 to 50 parts by weight with respect to 100 parts by weight of (a), the concentration of (c) is 0.01 to 10% by weight, and the concentration of (d) is 0.01 to 10 parts by weight. A microetching agent comprising 30% by weight and a halogen content of less than 0.01% by weight. (A) iron (III) sulfate, (b) sulfuric acid,
A microetching agent for copper and / or copper alloy, comprising an aqueous solution containing (c) a nonionic surfactant and (e) a carboxylic acid, wherein the concentration of (a) is 1 to 40% by weight. , (A) is 5 to 5 parts per 100 parts by weight.
0 parts by weight, and the concentration of (c) is 0.01 to 10 parts by weight.
A microetching agent having a concentration of (e) of 0.01 to 30% by weight and a halogen content of less than 0.01% by weight. (A) iron (III) sulfate, (b) sulfuric acid,
(C) a nonionic surfactant, (d) phosphoric acid and (e)
A copper and / or copper alloy microetching agent comprising an aqueous solution containing a carboxylic acid, wherein the concentration of (a) is 1 to 40% by weight, and (b) is 5 to 50 parts by weight, the concentration of (c) is 0.01 to 10% by weight, and the concentration of (d) is 0.01
A microetching agent characterized by having a concentration of (e) of 0.01 to 15% by weight and a halogen content of less than 0.01% by weight.