TWI489004B - Etching solution for copper and substrate manufacturing method - Google Patents

Description

Copper etching liquid and substrate manufacturing method

The present invention relates to an etching solution for copper containing sulfuric acid and hydrogen peroxide, and to a method for producing a substrate using the etching liquid.

In the manufacturing step of the printed wiring board, there is a semi-additive method as a method of forming wiring.

In the semi-additive method, a seed layer containing an electroless copper plating layer of about 0.5 to 2 μm is formed on the electrically insulating layer, and after forming a conductor thereon by electrolytic copper plating, unnecessary etching is removed by etching. The copper layer is electrolytically plated to form a wiring pattern.

As an etching liquid for removing the seed layer including the electroless plating layer, an etching solution such as sulfuric acid or hydrogen peroxide is known, for example, a azole is added to a hydrogen peroxide-sulfuric acid etching solution. Etc. (refer to Patent Documents 1 to 4).

The etching liquids are different in etching rate for electrolytic copper plating and electroless copper plating, and the seed layer containing the electroless copper plating layer is selectively etched without etching the conductor portion including the electrolytic copper plating layer.

However, there is a case where the surface of the electrical insulating layer is roughened in order to improve the adhesion between the electrical insulating layer and the seed layer. If the electrical insulating layer is used, the seed layer is embedded in the concave portion on the surface of the electrical insulating layer, and the adhesion between the two layers can be improved by the anchoring effect. However, when the seed layer is removed, the copper of the seed layer is embedded in the concave portion of the electrical insulating layer. Hard to remove.

In order to remove the copper embedded in the recess, etching for a long time is required, and the seed layer of the lower side portion of the conductor is etched in the horizontal direction, that is, a so-called undercut is generated, and when the undercut is large, there is a conductor. Peeling off.

Or there may be even a thinning of the conductor due to long-time etching.

Further, in recent years, a seed layer containing an electrolytic copper foil layer (electrolytic plating layer) and an electroless plating layer is provided on the surface of an insulating layer such as a resin instead of a seed layer containing only the electroless plating layer.

In this case, since the contour (concavo-convex shape) of the surface of the electrolytic copper foil directly becomes the shape of the surface of the resin, a recess is formed on the surface of the electrically insulating layer, and as described above, the copper portion of the seed layer remains in the concave portion. .

Further, as described above, an electroless copper plating layer is further formed on the surface of the electrolytic plating layer containing the electrolytic copper foil, and the seed layer including the electrolytic plating layer and the electroless plating layer is a conductor. It is necessary to etch both the electrolytic copper plating layer and the electroless copper plating layer after removing the seed layer of the non-conductor portion after formation.

In this case, if a previous etching liquid having a large difference in etching speed between the electrolytic copper plating layer and the electroless copper plating layer is used, only the electroless copper plating layer is horizontally in the seed layer of the two layers. Due to the large etching, the undercut is generated in a portion of the electroless plating layer, so that the conductor is peeled off before the seed layer is removed.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2005-5341

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2006-9122

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2006-13340

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2009-149971

In view of the above problems, an object of the present invention is to provide an etching solution for improving the removability of a seed layer, and which is difficult to generate an undercut, and a method for producing a substrate using the etching liquid.

The etching liquid of the present invention contains copper sulfate of sulfuric acid and hydrogen peroxide, and is characterized by comprising a benzotriazole compound having a nitro substituent and an organic amine compound.

Furthermore, the etching liquid of the present invention preferably contains 0.001% by mass or more and 0.2% by mass or less of the benzotriazole compound having a nitro substituent.

Further, the copper etching solution of the present invention preferably has a ratio of the etching rate ER1 of the electrolytic copper plating layer to the etching rate ER2 of the electroless copper plating layer of ER2/ER1 = 0.8 to 1.6.

Further, it is preferable that the organic amine compound is contained in an amount of 0.001% by mass or more and 1.0% by mass or less.

Further, the etching liquid of the present invention preferably has a chloride ion concentration of less than 2 ppm.

Further, in the method for producing a substrate of the present invention, a conductor layer is formed on the insulating base material via a seed layer including an electroless copper plating layer by electrolytic copper plating, and the conductor layer is formed after the conductor layer is formed. The copper etching solution etches the seed layer of the portion where the conductor layer is not formed.

Furthermore, the above etching solution of the present invention is a solution for etching copper, and the "copper" includes not only pure copper but also a copper alloy.

The etching liquid of the present invention is obtained by adding a benzotriazole compound having a nitro substituent and an organic amine compound to an etching solution containing sulfuric acid and hydrogen peroxide, thereby promoting the etching rate in the vertical direction.

Therefore, the seed layer exposed to the surface other than the conductor can be quickly removed, and when the seed layer is formed on the substrate having irregularities on the surface, the copper of the seed layer can be left in the concave portion of the substrate. Remove quickly.

Further, since the difference between the etching rate of the electrolytic copper plating layer and the etching rate for the electroless copper plating layer is a suitable range, it is possible to suppress the seed layer existing only under the conductor including the electrolytic copper plating (non-electrolytic layer) The copper plating layer is etched in the horizontal direction and the undercut is formed in the lower portion of the conductor. Further, since the seed layer can be removed in a short time, the entire conductor can be prevented from being thinned.

Further, when the seed layer containing the electroless plating layer is etched to form a substrate by using the etching liquid of the present invention, the seed layer can be removed without remaining on the electric insulating layer, and the generation of the conductor can be suppressed. Undercutting, so that the substrate can be manufactured with better yield.

Hereinafter, an embodiment of the present invention will be described.

The etching solution of this embodiment is a solution containing the following components (a) to (d):

(a) sulfuric acid,

(b) hydrogen peroxide,

(c) a benzotriazole compound having a nitro substituent,

(d) an organic amine compound.

The sulfuric acid of the component (a) and the hydrogen peroxide of the component (b) are base components.

The concentration of sulfuric acid in the etching solution is preferably from 0.5 to 50% by mass, more preferably from 1 to 20% by mass, still more preferably from 4 to 13% by mass.

When it is contained in an amount of 0.5% by mass or more, an appropriate etching rate for the electroless copper plating layer can be formed, and when it is contained in an amount of 50% by mass or less, the dissolved copper can be prevented from being precipitated as copper sulfate.

The concentration of hydrogen peroxide in the etching solution is preferably from 0.1 to 7% by mass, more preferably from 0.2 to 5% by mass, still more preferably from 0.6 to 2.5% by mass.

When the hydrogen peroxide concentration is 0.1% by mass or more, the etching rate for the electroless copper plating layer can be set to an appropriate range, and when the hydrogen peroxide concentration is 7% by mass or less, the heat of reaction can be suppressed. The etching speed is excessively increased.

The rate of etching copper in the vertical direction can be promoted by adding the above benzotriazole compound having a nitro substituent.

In particular, in the case of performing a spray treatment, and spraying the surface of the seed layer from above, etching in the spray direction of the spray can be promoted.

Examples of the benzotriazole compound having a nitro substituent as the component (c) include 4-nitrobenzotriazole, 5-nitrobenzotriazole, and 6-nitro-1-hydroxybenzone. Triazole and the like.

The concentration of the component (c) in the etching solution is preferably 0.001% by mass to 0.2% by mass, more preferably 0.005% by mass to 0.09% by mass, still more preferably 0.01% by mass to 0.06% by mass.

If it is in the above concentration range, the effect of promoting the etching rate in the vertical direction can be obtained.

By adding the organic amine compound of the above component (d), the difference between the etching rate of the electrolytic copper plating layer and the etching rate for the electroless copper plating layer can be reduced.

Generally, in an etching solution in which sulfuric acid and hydrogen peroxide are used as a base material, since the etching speed of the electroless copper plating layer is fast, when the electrolytic copper plating layer and the electroless copper plating layer are mixed, the etching is preferentially performed. Electrolytic copper plating. That is, when the seed layer contains the electroless copper plating layer, the electroless copper plating layer can be removed without etching the conductor, but at the same time, the seed layer exposed to the side surface of the conductor is etched from the horizontal direction, resulting in excessive etching. The undercut of the lower part of the conductor.

Since the etching liquid of the present invention contains the above component (d), the difference between the etching rate of the electrolytic copper plating layer and the etching rate for the electroless copper plating layer is small, that is, even the electrolytic copper plating layer and the electroless copper plating layer. The layers are all exposed from the side of the conductor, and it is also possible to suppress over-etching of the electroless copper plating layer to cause undercut.

As the organic amine compound of the component (d), a methylenedimine, an alkylamine, a cycloalkylamine, a cycloalkylimine, an ethylene oxide, and/or a propylene oxide can be used. .

Preferred examples of the alkylene imine include methylimine, ethyleneimine, butylimine, propyleneimine, imipenem, heximide, exonumine, and eximide. In addition, polymethylenimine, ethylenediamine, triamethylenetetramine, propylenediamine, decamethyldiamine, dioctylamine, diamethylenetriamine, and propylenetriamine , tetraethyleneamine, trimethylenediamine, pentaethyleneamine, dipropylenetriamine, 2-heptyl-3-(2-aminopropyl)-imidazoline, 4-methyl Imidazoline, N,N-dimethyl-1,3-propanediamine, 1,3-bis(2-aminoethyl)imidazoline, 1-(2-aminopropyl)-peri 1,4-bis(2-aminoethyl)per And 2-methyl-1-(2-aminobutyl)per Wait.

In particular, as a preferred alkylene imide, an alkyleneimine having 2 to 8 carbon atoms such as ethylenediamine, excipient, and trimethylenediamine may be mentioned.

The alkylamine may, for example, be methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, N,N-dimethylamine, N,N-diethylamine, N,N-dipropylamine or N. An alkylamine having an alkyl group having 1 to 4 carbon atoms, such as N-dibutylamine, trimethylamine, triethylamine, tripropylamine or tributylamine.

In particular, preferred alkylamines include alkylamines having 2 to 8 carbon atoms such as ethylamine, hexylamine and triethylamine.

Examples of the cycloalkylamine include a cycloalkylamine having 3 to 8 carbon atoms such as cyclopropylamine, cyclobutylamine, cyclopentylamine, cyclohexylamine, and cyclooctylamine.

Further, examples of the cycloalkylimine include a cycloalkyleneimine having a carbon number of 3 to 8 such as a cyclobutylimine, a cyclopentimine or a cycloheximide.

The addition of ethylene oxide (EO) and/or propylene oxide (PO) to the above alkylene imine or alkylamine can be used, and preferably ethylene oxide (EO) is 2~. 60 moles and propylene oxide (PO) are preferably added in a ratio of 2 to 80 moles.

The concentration of the component (d) in the etching solution is preferably 0.001% by mass to 1% by mass, more preferably 0.02% by mass to 0.5% by mass, still more preferably 0.04% by mass to 0.26% by mass.

If it is in the above concentration range, the etching rate of the electrolytic copper plating layer and the electroless copper plating layer can be adjusted to a suitable range.

The etching rate ER1 of the etching solution of the present embodiment to the electrolytic copper plating layer is preferably 0.2 to 5 μm/min., and the etching rate ER2 for the electroless copper plating layer is preferably in the range of 0.2 to 8 μm/min.

Further preferably, the ratio of the etching rate ER1 of the electrolytic copper plating layer to the etching rate ER2 of the electroless copper plating layer is ER2/ER1 = 0.8 to 1.6.

In order to form the etching rate ratio described above, the concentration of the component (d) can be adjusted to the concentration range as described above as described above.

Further, the chloride ion concentration in the etching solution of the present embodiment is preferably less than 2 ppm, more preferably less than 1 ppm, and even more preferably less than 0.25 ppm.

When the chloride ion concentration is less than the above concentration, the seed layer can be removed without roughening the surface of the conductor and maintaining the smoothness.

The etching solution of the present embodiment can be easily prepared by dissolving the above components in a solvent such as water. In the case where water is used as the solvent, water which removes ionic substances or impurities is preferable, and for example, ion-exchanged water, pure water, ultrapure water or the like is preferable.

Further, in the etching liquid of the present embodiment, the above components may be blended so as to have a specific concentration, or a concentrate may be prepared in advance and diluted and used immediately before use.

Next, a method of manufacturing a substrate by a semi-additive method using the etching liquid of the present embodiment will be described.

The method for producing a substrate according to the present embodiment is used, for example, in a copper resin laminated sheet obtained by using a substrate surface layer of an insulating resin to form a copper resin laminated sheet, and a conductor pattern is formed by a semi-additive method.

The electrolytic copper foil is usually an electrolytic copper foil having an electrolytic copper plating layer having a thickness of about 1.5 μm to 5 μm formed on the surface of a carrier by electrolytic copper plating, and supported by a carrier.

The electrolytic copper foil is laminated on both surfaces of the prepreg resin as an electrical insulating layer, and pressed while being heated, whereby a copper resin laminated sheet including an electrolytic copper foil layer and an electrically insulating layer can be formed.

As the electrical insulating layer, a glass epoxy resin sheet having a thickness of about 0.2 mm to 0.6 mm is usually used.

The above-mentioned electrolytic copper foil usually has irregularities (especially a matte surface) on the surface, and the surface of the resin which is pressed under the state of pressing the surface of the electrolytic copper foil is also uneven, and the copper of the copper foil is trapped in the concave portion. Layering is performed in the state.

The copper resin laminated sheet was immersed in an electroless copper plating solution, and an electroless copper plating layer was formed on both surfaces of the laminated sheet.

The electroless copper plating layer is usually preferably formed to have a thickness of 0.5 to 1.5 μm.

Further, as the electroless copper plating solution, a known plating solution can be appropriately selected and used.

As described above, the seed layer is formed of the above-mentioned electrolytic copper foil layer (electrolytic copper plating layer) and the electroless copper plating layer.

Then, a photoresist pattern is formed on the seed layer by an anti-plating layer such as a dry film photoresist, and then a conductor layer having a thickness of 15 to 25 μm is formed by electrolytic copper plating.

Thereafter, the plating resist is peeled off by an anti-plating layer peeling liquid such as sodium hydroxide to form a conductor pattern.

At this time, since the seed layer is left in a portion other than the conductor, the seed layer is etched by the etching liquid of the present invention to remove the unnecessary seed layer.

As the etching method, the seed layer may be brought into contact with the etching liquid by a known method such as spraying or dipping, for example, in the case of spraying by spraying, and also depending on the thickness of the seed layer, and it is usually preferred. For the liquid temperature of 15 ~ 40 ° C, the spray pressure of 0.05 ~ 0.20 MPa, spraying time of about 30 ~ 180 seconds.

As described above, the etching solution of the present invention has a small difference in etching speed between the electroless copper plating layer and the electrolytic copper plating layer, and the etching speed in the vertical direction is faster, so that the seed layer can be removed to manufacture the substrate instead of The copper of the seed layer remains in the concave portion of the surface of the insulating resin layer, and no large undercut is generated.

Further, in the above embodiment, a case where a seed layer containing an electrolytic copper plating layer containing an electrolytic copper foil and an electroless copper plating layer is formed on the electrically insulating layer will be described. However, the seed layer may be Only those containing electroless copper plating.

In this case, in order to improve the adhesion to the electroless copper plating layer, for example, the surface of the electric insulating layer may be roughened by a chemical or the like, and the seed crystal may be etched by using the etching liquid of the present embodiment as described above. The layer is etched to completely remove the seed layer without tapering the conductor or stripping the conductor itself.

[Examples]

Hereinafter, the etching liquid of the present invention and the method of producing the substrate using the etching liquid will be described by way of examples and comparative examples. Furthermore, the present invention is not limited to the following examples and explained.

(etching solution)

Various solutions of the compositions shown in Tables 1 and 2 were prepared. Further, the remainder except the components shown in Tables 1 and 2 is ion-exchanged water.

Further, the details of the compound names described in the respective tables are as follows.

4N-BTA: 4-nitrobenzotriazole

5N-BTA: 5-nitrobenzotriazole

Adeka Pluronic TR-704: manufactured by Adeka Co., Ltd. Ethylenediamine EO‧PO adduct

Adeka Pluronic TR-702: manufactured by Adeka Co., Ltd. Ethylenediamine EO‧PO adduct

Adeka Pluronic TR-913R: manufactured by Adeka Co., Ltd. Ethylenediamine EO‧PO adduct

MI-002: Manufactured by First Industrial Pharmaceutical Co., Ltd. Polyoxyalkylene alicyclic amine EO‧PO adduct

SANHIBITOR No.50M: Sanyo Chemical Co., Ltd. Cyclohexylamine EO‧PO adduct

Ethopropomeen C18/18: manufactured by Lion Akzo Co., Ltd. amine alkylene oxide EO‧PO 16 molar addition

4A-BTA: 4-aminobenzotriazole

EDA: Ethylenediamine

Methyl CHA: methylcyclohexylamine

Rikemal B-205: Riken Vitamin Co., Ltd. EO 5 molar additive of polyoxyethylene alkyl ether

LEOCON 5030B: Lion Co., Ltd. Polyoxypropylene polyoxyethylene monobutyl ether EO‧PO adduct

(Measurement of etching rate ER1 of electrolytic copper plating layer)

A copper-clad laminate having an electrolytic copper foil layer laminated on both sides of an electrically insulating resin layer is prepared by 50 mm × 50 mm (manufactured by Matsushita Electric Works Co., Ltd., trade name: Glass Epoxy Multi R-1766), and electrolysis of the copper-clad laminate A test substrate for measuring the etching rate ER1 of the electrolytic copper plating layer was prepared by fully performing electrical copper plating having a thickness of 15 μm on the copper foil layer.

The test substrate was etched by spraying treatment (spray pressure: 0.05 MPa, temperature: 30 ° C) for 15 seconds to 1 minute using each etching liquid described in each table, and the weight of the test substrate before and after the treatment was used according to the following formula. The etching rate ER1 (μm/min.) for electrolytic copper plating was calculated by the difference between the difference and the weight of the test substrate before and after the treatment.

ER1 (μm/min.) = (weight before treatment (g) - weight after treatment (g)) ÷ test substrate area (m ² ) density of yttrium copper (g/cm ³ ) ÷ treatment time (min.)

(Measurement of etching rate ER2 of electroless copper plating layer)

A copper clad laminate having a thickness of 0.2 mm of an electrolytic copper foil layer (manufactured by Matsushita Electric Works Co., Ltd., trade name: Glass Epoxy Multi R-1766) was laminated on both sides of the electrically insulating resin layer, and the copper clad laminate was immersed in In the copper foil removal liquid containing 200 g/L of sulfuric acid, 50 g/L of hydrogen peroxide, and the remainder being ion-exchanged water, the electrolytic copper foil layer of the copper-clad laminate was completely removed.

The electroless copper plating chemical liquid (product name: OPC-COPPER H) manufactured by Okuno Pharmaceutical Co., Ltd. was plated on one side of the exposed glass epoxy substrate at a plating condition of 30 ° C for 75 minutes. , an electroless copper plating layer having a thickness of 1.5 μm is formed in an all-round manner.

The test substrate for measuring the etching rate of electroless copper plating was used as a test substrate for measuring the etching rate of electroless copper plating, and each of the etching liquids described in each table was sprayed for 15 seconds (spray pressure: 0.05 MPa). Each test substrate was etched at a temperature of 30 ° C.

The etching rate ER2 (μm/min.) for electroless copper plating was calculated from the weight of the test substrate before and after the treatment according to the following formula.

ER2 (μm/min.) = (weight before treatment (g) - weight after treatment (g)) ÷ substrate area (m ² ) ÷ copper density (g/cm ³ ) ÷ treatment time (min.)

(Evaluation of the removal of electrolytic copper plating)

A copper foil (product name: Micro Thin Ex) made by Mitsui Metals Mining Co., Ltd., which is 3 μm thick, is laminated on a prepreg manufactured by Matsushita Electric Works Co., Ltd. with a thickness of 0.2 mm (product name: High Heat Resistant Glass Epoxy Multi R) On both sides of the -1661) (electrolytic copper plating layer), after peeling off the carrier foil, it was cut into 100 mm × 100 mm.

The electroless plating chemical (product name: OPC-COPPER H) manufactured by Okuno Pharmaceutical Co., Ltd. was plated at 30 ° C for 50 minutes, and the thickness of the laminated plate was 1 μm. Electroless copper plating.

Further, the electroless copper plating layer was plated with a photosensitive dry film (product name: SUNFORT ASG-254) manufactured by Asahi Kasei Electronics Co., Ltd., and electroplated with copper at 2.0 A/dm ² for 55 minutes. The plating treatment was carried out to form a wiring pattern having a thickness of 18 μm (line/gap = 25 μm / 25 μm).

Thereafter, a 3% by weight aqueous sodium hydroxide solution was sprayed to peel off the plating resist layer to prepare a test substrate for seed layer removal evaluation.

Using the respective etching liquids described in the respective tables, the test substrate was etched by a spray treatment (spray pressure: 0.05 MPa, temperature: 30 ° C), and the removal time until the seed layer between the conductors was completely removed (electrolytic plating) Copper layer removal time).

In addition, the removal of the seed layer between the conductors was confirmed by visual observation by magnifying 500 times with a metal microscope (MX50 manufactured by Olympus Co., Ltd.).

(Evaluation of the removal of electroless copper plating)

A copper clad laminate having a thickness of 0.2 mm (manufactured by Matsushita Electric Works, trade name: Glass Epoxy Multi R-1766) was prepared, and the copper clad laminate was immersed in 200 g/L of sulfuric acid and 50 g/L of hydrogen peroxide. The remaining portion is a copper foil removal liquid of ion-exchanged water, and the electrolytic copper foil layer of the copper-clad laminate is completely removed, and an electroless copper plating chemical (product name: OPC-COPPER H) manufactured by Okuno Pharmaceutical Co., Ltd. is used, 30 The plating conditions of one of the exposed glass epoxy substrates were plated at ° C for 50 minutes, and an electroless copper plating layer (electroless copper seed layer) having a thickness of 1 μm was formed. Prepare it to cut into a 100 mm × 100 mm substrate. The substrate was subjected to a plating resist pattern by a photosensitive dry film (product name: SUNFORT ASG-254) manufactured by Asahi Kasei Electronics Co., Ltd., and electroplated with copper, and plated under 2.0 A/dm ² , 55 minutes plating conditions. Processing to form a wiring pattern having a thickness of 18 μm (line/gap = 15 μm / 15 μm).

Thereafter, a 3% by weight aqueous sodium hydroxide solution was sprayed to peel off the plating resist layer to prepare a test substrate for evaluation of the electroless copper plating seed layer.

Using the respective etching liquids described in the respective tables, the test substrate was etched by a spray treatment (spray pressure: 0.05 MPa, temperature: 30 ° C), and the removal time until the seed layer between the conductors was completely removed was measured. Electrolytic copper plating removal time).

In addition, the removal of the seed layer between the conductors was confirmed by visual observation by magnifying 500 times with a metal microscope (MX50 manufactured by Olympus Co., Ltd.).

(Measurement of the amount of conductor thinning)

In the test substrate on which the above various crystal layer removal evaluations were performed, the width of the top of the conductor before and after the removal of the various crystal layers was measured, and the extent to which the conductor was thinned after the seed layer was removed was measured.

In addition, the width of the top of the conductor was measured by a digital microscope (manufactured by KEYENCE, VHX), and 10 parts were measured in total, and the average value was taken.

Conductor thinning amount (μm) = conductor top width (μm) before processing - treated conductor top width (μm)

(Method for measuring undercut length (UCL))

The test substrate subjected to the measurement and evaluation of the above-described conductor thinning amount was subjected to embedding treatment using an embedding resin, and was cut and subjected to cross-section polishing.

Then, the polishing profile was observed with a digital microscope (manufactured by KEYENCE, VHX), and the undercut length of each test substrate was measured by the following method.

Determination of UCL after removal of electrolytic copper plating

The total difference between the width of the interface between the conductor and the electroless copper plating layer and the width of the interface between the electroless copper plating layer and the electrolytic copper plating layer on the lower side of the total of 10 parts is calculated, and the average value is calculated. The average of 2 is taken as UCL.

Determination of UCL after removal of electroless copper plating

For the total of 10 locations, the width of the interface between the conductor and the electroless copper plating layer and the difference between the width of the interface between the electroless copper plating layer and the glass epoxy substrate were measured, and the average value was calculated, and the average value was 1/2. As UCL.

(Measurement of thickness)

The thickness Rz (μm) of the conductor surface of each test substrate after the evaluation of the electrolytic copper plating layer removability was measured by a laser microscope (OLS-1100, manufactured by Olympus Co., Ltd.).

The results of each measurement are shown in the table.

From the above results, it is clear that in the examples, the removal time of the electrolytic plating layer was shorter, and the amount of the conductor thinning and the amount of the undercut were less, and the surface of the conductor was not roughened as compared with the comparative example.

Claims (6)

An etching solution for copper containing sulfuric acid and hydrogen peroxide, characterized by comprising a benzotriazole compound having a nitro substituent and an organic amine compound, and the above organic amine compound is added to an epoxy compound In the case of ethane and/or propylene oxide, the compound is one or more selected from the group consisting of alkylene imine, alkylamine, cycloalkylamine and cycloalkylimine. The copper etching solution according to claim 1, wherein the benzotriazole compound having a nitro substituent is contained in an amount of 0.001% by mass or more and 0.2% by mass or less. The copper etching solution according to claim 1, wherein the organic amine compound contains 0.001% by mass or more and 1.0% by mass or less. The ratio of the etching rate ER1 of the electrolytic copper plating layer to the etching rate ER2 of the electroless copper plating layer is ER2/ER1=0.8 to 1.6, as in the copper etching solution of claim 1. The copper etching solution of claim 1 has a chloride ion concentration of less than 2 ppm. A method for producing a substrate, wherein a conductor layer is formed on an insulating substrate via a seed layer including an electroless copper plating layer by electrolytic copper plating, wherein after the conductor layer is formed, as requested The copper etching solution according to any one of items 1 to 5 etches the seed layer of the portion in which the conductor layer is not formed.