JP2001181868A - Microetching agent for copper and copper alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microetching agent capable of executing microetching free from the generation of 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) 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 to 20 wt.%, and suitably, (d) phosphoric acid of 0.01 to 30 wt.%, or (e) carboxylic acid of 0.01 to 30 wt.%, or (d) phosphoric acid of 0.01 to 15 wt.% and (e) 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 causes uneven etching when fine dirt such as an oil component is present on the copper surface. Accordingly, an object of the present invention is to provide a microetching agent capable of performing good microetching without causing uneven etching even when fine dirt such as an oil component is present on the copper surface.

[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 to 3. (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 0.1 to 10% by weight. 01
-20% by weight, and the present invention further comprises (d) 0.01-30% by weight of phosphoric acid, or (e) 0.01-30% by weight of carboxylic acid,
Alternatively, it is a microetching agent containing (d) 0.01 to 15% by weight of phosphoric acid and (e) 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 alkylene oxide addition thereof can be used. Products, 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, nonionics such as polyalkylene oxides Surfactants 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.

Of the above-mentioned (c) nonionic surfactants, particularly when it is desired to 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 is particularly preferable to use a propylene oxide / ethylene oxide random adduct of propylene glycol, which is more preferably propylene oxide / ethylene oxide = 2: 8 to 4: 6 mol. It is preferable to use those having a ratio 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 microetchant of the present invention contains the carboxylic acid (e) as a fourth component in an amount of from 0.01 to 0.01%.
It can be used at a concentration of 30% by weight, preferably 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 limited. For example, formic acid,
Acetic acid, propionic acid, butyric acid, valeric acid, aliphatic saturated carboxylic acids such as caproic acid, acrylic acid, methacrylic acid, crotonic acid, and aliphatic unsaturated carboxylic acids such as irocrotonic acid;
Aliphatic saturated dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid and pimelic acid; aliphatic unsaturated dicarboxylic acids such as maleic acid; aromatic carboxylic acids such as benzoic acid, phthalic acid and cinnamic acid , Glycolic acid, lactic acid, malic acid, tartaric acid, oxycarboxylic acids such as citric acid, sulfamic acid, β-chloropropionic acid, nicotinic acid, ascorbic acid, hydroxypivalic acid, carboxylic acid having a substituent such as levulinic acid, and These derivatives may be mentioned.

The above-mentioned microetching agent of the present invention comprises (d) phosphoric acid and (e) as a fourth component and a fifth component.
When a carboxylic acid is used in combination, a more effective and preferable microetching agent is obtained. In this case, the range of the amount of each of these (d) phosphoric acid and (e) carboxylic acid is (d) =
0.01 to 15% by weight, (e) = 0.01 to 15% by weight
Which can be set independently of each other. The effects when the amounts of these (d) 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 0.01 to 20% by weight. Outside the above range (too much or too little), a copper surface with good adhesion and solderability between the copper surface and the resin will not be obtained. The type of halogen is not particularly limited, and chlorine, bromine and the like are used, but chlorine is preferred from the industrial suitability. As a halogen source,
There is no particular limitation as long as it can release halogen ions in an aqueous solution. Examples thereof include hydrochloric acid, hydrobromic acid, sodium chloride, sodium bromide, potassium chloride, potassium bromide, calcium chloride, calcium bromide, and ammonium chloride. , Ammonium bromide, copper chloride, zinc chloride, iron chloride, tin bromide, copper bromide, etc., and chlorine gas may be blown. These may be used alone or in combination of two or more. In addition, for example, iron chloride (II
I) has the ability to etch copper similarly to the above (a) iron (III) sulfate, so that iron chloride (II) is used as a halogen source.
If I) is selected, the amount of (a) iron (III) sulfate used is less than 10% and the total amount of (a) iron (III) sulfate and iron (III) chloride is above (a) It is necessary not to exceed the upper limit of the amount of (III) used. Further, for example, since hydrochloric acid has properties similar to the above-mentioned (b) sulfuric acid, when hydrochloric acid is selected as the halogen source, the amount of (b) sulfuric acid used is less than 10% and (b) the sum of sulfuric acid and hydrochloric acid It is necessary that the amount does not exceed the upper limit of the amount of (b) sulfuric acid used.

[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.

[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]

[Adhesiveness] A prepreg having a thickness of 0.15 mm was heated and pressed on a copper-clad laminate treated in the same manner as in Example 1 with the composition shown in Table 7, and the peel strength was evaluated in accordance with JIS C 6481 (1990). The results were good as shown in Table 7.

[0028]

[Table 7]

[0029]

The effect of the present invention is to provide a micro-etching agent which can perform good micro-etching without causing uneven etching even if fine dirt such as an oil component exists on the copper surface. .

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ryoji Kabeya Asahi Denka Kako Kogyo Co., Ltd., 7-2-35 Higashiogu, Arakawa-ku, Tokyo (72) Inventor Yoshitsugu Ishizuka 7-2 Higashiogu, Arakawa-ku, Tokyo No. 35 Asahi Denka Kogyo Co., Ltd. (72) Inventor Kazutada Komura 7-35 Higashi Oku, Arakawa-ku, Tokyo Asahi Denka Kogyo Co., Ltd. F-term (reference) 4K057 WA10 WB04 WE03 WE04 WE08 WE09 WF10

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 0.01 to 20% by weight. Characterized micro-etching 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. 30% by weight and a halogen content of 0.01 to 20% 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 0.01 to 20% by weight. (A) iron (III) sulfate, (b) sulfuric acid,
(C) a nonionic surfactant, (d) phosphoric acid and (e)
A microetching agent for copper and / or copper alloy comprising an aqueous solution containing a carboxylic acid, wherein the concentration of (a) is 1 to 40% by weight, and (b) is based on 100 parts by weight of (a). Is a ratio of 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 0.01 to 20% by weight.