JP2023082924A - Acidic degreaser - Google Patents

Abstract

To provide an acidic degreaser for use in pretreatment of electric copper pattern plating, wherein the acidic degreaser barely causes floating or peeling between a resist pattern and a seed layer, and excels in degreasing power and wettability to the surfaces of the seed layer and the resist material.SOLUTION: An acidic degreaser is for use in pretreatment of electric copper pattern plating and comprises specific amounts of at least one acid selected from the group consisting of sulfuric acid and organic acid, a polyoxyalkylene alkyl ether-based nonionic surfactant, and a chloride ion source. When used, the acidic degreaser has a solution temperature of 15°C-35°C.SELECTED DRAWING: Figure 9

Description

TECHNICAL FIELD The invention pertaining to the present application relates to an acidic degreasing agent used for pretreatment of electrolytic copper pattern plating.

In general, when a printed wiring board is produced by electrolytic copper pattern plating, first, a seed layer, which is a metal thin film, is provided on the surface of an insulating substrate, and then a dry film photoresist (hereinafter referred to as "dry film resist or DFR"). ) or the like is used to form a resist pattern. Electrolytic copper plating is applied to this to form a metal film made of copper or copper alloy, unnecessary portions where the resist material and seed layer are laminated are removed from the surface of the insulating substrate, and a substrate with a conductor circuit pattern is obtained. (that is, a printed wiring board) is obtained.

Here, as a pretreatment for electrolytic copper pattern plating, the seed layer and the insulating substrate with the resist pattern are subjected to degreasing, cleaning, and the like. If the solution used for this degreasing treatment is alkaline, the dry film resist may react with alkaline components in the solution, causing problems such as corrosion, pulverization, and peeling. Therefore, a method using an acidic degreasing agent is adopted. According to this method, oils and fats remaining on the surface of the seed layer and the resist material can be satisfactorily removed without corroding the dry film resist, and natural oxide films, rust, etc., formed on the surface of the seed layer can also be removed. It can be said that it is excellent in

As this type of acidic degreasing agent, Patent Document 1 describes "(A) an acid selected from divalent carboxylic acids or alkanesulfonic acids, (B) an acid selected from the group consisting of hydrochloric acid, sulfuric acid, phosphoric acid and nitric acid. An acidic degreasing agent containing (C) an alkylbenzene sulfonate and (D) a surfactant having an acetylene bond in the molecule” is disclosed.

JP-A-2001-89882

However, when the pretreatment of electrolytic copper pattern plating is performed using a conventional acidic degreasing agent such as that disclosed in Patent Document 1, the acidic degreasing agent may affect the resist pattern unexpectedly depending on the contained components, their concentrations, processing conditions, and the like. could have an unintended effect. As a result, lift or peeling occurs between the resist pattern and the seed layer, causing problems such as deposition of copper or copper alloy metal components under the resist material during copper electroplating. rice field. On the other hand, when an acidic degreasing agent that does not corrode the resist pattern and its treatment conditions are used, the degreasing power and wettability with respect to the surface of the seed layer are insufficient, resulting in a problem that a high-quality product cannot be obtained.

Therefore, among those skilled in the art, it is extremely difficult to cause lifting or peeling between the resist pattern and the seed layer, and it is excellent in degreasing power and wettability with respect to the surface of the seed layer, and is used for pretreatment of electrolytic copper pattern plating. drug is sought.

Therefore, as a result of earnest research, the inventor of the present invention has achieved this problem by adopting the following method.

The acidic degreasing agent according to the present application is used for pretreatment of electrolytic copper pattern plating, and contains 0.1% to 20% by mass of one or more acids selected from the group consisting of sulfuric acid and organic acids, poly 0.01% to 1% by mass of an oxyalkylene alkyl ether type nonionic surfactant, 0.001% to 1% by mass of a chloride ion source in terms of chloride ion concentration, liquid temperature at the time of use is 15°C to 35°C.

In the acidic degreasing agent according to the present application, the organic acid is selected from the group consisting of citric acid, formic acid, acetic acid, propionic acid, glycolic acid, malic acid, oxalic acid, succinic acid, maleic acid, methanesulfonic acid, lactic acid, and tartaric acid. preferably one or more of the

In the acidic degreasing agent according to the present application, the polyoxyalkylene alkyl ether type nonionic surfactant is preferably one or more represented by the following general formula (1) or general formula (2).
R ₁ —O—(EO) _m —(AO) _n —H (1)
R ₁ —O—(AO) _n —(EO) _m —H (2)
(In general formulas (1) and (2), R ₁ is a linear or branched alkyl group having 3 to 20 carbon atoms, EO is an oxyethylene group, and m represents the number of repetitions of EO from 2 to is an integer of 20. AO represents PO (oxypropylene group) or BO (oxybutylene group), and n is an integer of 0 to 20 indicating the number of repetitions of AO.)

The acidic degreasing agent according to the present application has a chloride ion source containing sodium chloride, hydrochloric acid, copper chloride, ammonium chloride, lithium chloride, potassium chloride, magnesium chloride, calcium chloride, vanadium chloride, manganese chloride, iron chloride, cobalt chloride, It is preferably one or more selected from the group consisting of nickel chloride and zinc chloride.

According to the invention of the present application, it is extremely difficult for lifting or peeling to occur between the resist pattern and the seed layer, and the electrolytic copper pattern plating is excellent in degreasing power, wettability with respect to the seed layer and the resist material surface, etc. It is possible to provide an acidic degreasing agent used for pretreatment of.

(a) to (g) are an insulating substrate with a seed layer and a resist pattern (that is, copper with a resist pattern having an electroless copper plating film) in Examples 1 to 7 using the acidic degreasing agent of the present application It is a metallurgical microscope observation image of a laminated sheet) viewed from above. (a) to (e) are metallurgical microscope observation images of insulating substrates with a seed layer and a resist pattern in Examples 8 to 12 using the acidic degreasing agent of the present application, as viewed from above. (a) to (d) are metallurgical microscope observation images from above of the insulating substrate with the seed layer and the resist pattern in Examples 13 to 16 using the acidic degreasing agent of the present application. (a) to (c) are metallurgical microscope observation images of insulating substrates with a seed layer and a resist pattern in Examples 17 to 19 using the acidic degreasing agent of the present application. (a) to (d) are metallurgical microscope observation images of insulating substrates with seed layers and resist patterns in Comparative Examples 1 to 4 using acidic degreasing agents with different concentration conditions, as viewed from above. (a) to (g) are metallurgical microscopes of top views of insulating substrates with seed layers and resist patterns in Comparative Examples 5 to 11 using acidic degreasing agents having different compositions and/or liquid temperatures during use. This is an observation image. (a) and (b) are metallurgical microscope observation images of insulating substrates with a seed layer and a resist pattern in Comparative Examples 12 and 13 using acidic degreasing agents with different concentration conditions, as viewed from above. (a) and (b) are metallurgical microscope observation images of insulating substrates with a seed layer and a resist pattern in Comparative Examples 14 and 15 using acidic degreasing agents with different concentration conditions, as viewed from above. (a) and (b) show seed layers and resist patterns in Example 18 using the acidic degreasing agent of the present application and Comparative Example 7 using an acidic degreasing agent with a different composition and liquid temperature during use. It is a cross-sectional observation image of the test piece which electro-copper-plated to the insulating board|substrate with.

Embodiments of the acidic degreasing agent according to the present application will be described below with reference to FIGS. 1 to 9. FIG.

The acidic degreasing agent according to the present application is used for pretreatment of electrolytic copper pattern plating, and contains "one or more acids selected from the group consisting of sulfuric acid and organic acids" and "polyoxyalkylene alkyl ether type It contains predetermined amounts of a nonionic surfactant and a chloride ion source, and has a liquid temperature of 15°C to 35°C during use.

A. Ingredients of Acidic Degreasing Agent Each ingredient of the acidic degreasing agent of the present application will be described below.

A-1. Acid component The acid component is the main ingredient in the acidic degreasing agent and consists of one or more of sulfuric acid and organic acid. This acid component degreases and cleans stains such as oils and fats adhering to the seed layer made of copper or copper alloy on the insulating substrate and the surface of the resist material, and removes the natural oxide film etc. formed on the surface of the seed layer. It has a function.

Among these acid components, organic acids include citric acid, formic acid, acetic acid, propionic acid, glycolic acid, malic acid, oxalic acid, succinic acid, maleic acid, methanesulfonic acid, lactic acid, and tartaric acid.

Also, the content of the acid component in the acidic degreasing agent is 0.1% by mass to 20% by mass. If the content of the acid component is less than 0.1% by mass, the effect of degreasing and cleaning stains such as oils and fats adhering to the surface of the seed layer and the resist material on the insulating substrate is reduced, and the surface of the seed layer is contaminated. Also, the effect of removing the natural oxide film, etc. tends to be reduced, which is not preferable. On the other hand, if the content of the acid component exceeds 20% by mass, the acidic degreasing agent tends to corrode the resist material, causing lifting or peeling between the resist pattern and the seed layer, which is not preferable. The content of the acid component is more preferably 1% to 20% by mass, still more preferably 5% to 15% by mass. When the content of the acid component is 1% by mass to 20% by mass, the effect of degreasing and cleaning stains such as oil and fat adhering to the surface of the seed layer and the resist material tends to be further improved, and the content of the acid component tends to be improved. This is because when the content is 5% by mass to 15% by mass, the effect tends to be most improved and the cost effectiveness is high. When the acidic degreasing agent contains two or more acid components, the content of the acid components is described as the total content.

A-2. Polyoxyalkylene Alkyl Ether Type Nonionic Surfactant Nonionic (also referred to as “nonionic or nonionic”) surfactants have the advantage of being excellent in emulsifying and solubilizing power and causing little foaming. Among these nonionic surfactants, the most industrially used representative one is the polyoxyalkylene alkyl ether type nonionic surfactant. The polyoxyalkylene alkyl ether type nonionic surfactant is an ether type surfactant obtained by mainly adding alkylene oxide to alcohol, and is an acidic degreasing agent without adding a separate alcohol compound. It has an excellent function of being able to effectively lower the surface tension.

This polyoxyalkylene alkyl ether type nonionic surfactant is preferably one or more than one represented by the following general formula (1) or general formula (2).

R ₁ —O—(EO) _m —(AO) _n —H (1)
R ₁ —O—(AO) _n —(EO) _m —H (2)
However, in general formulas (1) and (2), R ₁ is a linear or branched alkyl group having 3 to 20 carbon atoms. EO is an oxyethylene group, and m is an integer of 2 to 20 indicating the number of repetitions of EO. AO represents PO (oxypropylene group) or BO (oxybutylene group), and n is an integer of 0 to 20 indicating the number of repetitions of AO.

In general formulas (1) and (2) above, if the number of carbon atoms in R ₁ is less than 3, the degreasing power of the acidic degreasing agent tends to decrease, which is not preferred. On the other hand, when the number of carbon atoms in R ₁ exceeds 20, the solubility in water as a solvent tends to decrease, which is not preferable. The carbon number of R ₁ is more preferably 5-18, still more preferably 7-16. When R ₁ has 5 to 18 carbon atoms, the degreasing power of the acidic degreasing agent and its solubility in water tend to be further improved, and when R ₁ has 7 to 16 carbon atoms, this tendency is highest. It's for. Furthermore, it is more preferable that R ₁ is a branched alkyl group, since the degreasing power of the acidic degreasing agent tends to be improved.

Further, in the general formulas (1) and (2), if m is less than 2, the solubility in water, which is the solvent, tends to decrease, which is not preferable. On the other hand, if m exceeds 20, the degreasing power of the acidic degreasing agent tends to decrease, which is not preferable. Further, when m is 4 to 15, the solubility in water and the degreasing power of the acidic degreasing agent tend to be improved, which is more preferable.

In general formulas (1) and (2) above, if n exceeds 20, the solubility in water, which is the solvent, tends to decrease, which is not preferred. Further, when n is 0 to 15, the stability of the acidic degreasing agent tends to increase in a high-temperature environment, which is more preferable.

The content of the polyoxyalkylene alkyl ether type nonionic surfactant in the acidic degreasing agent is 0.01% by mass to 1% by mass. When the content of the polyoxyalkylene alkyl ether type nonionic surfactant is less than 0.01% by mass, the surface tension of the acidic degreasing agent is increased, and the wettability of the acidic degreasing agent to the seed layer and the resist material surface is reduced. As it decreases, the degreasing power of the acidic degreasing agent tends to decrease, which is not preferable. On the other hand, if the content of the polyoxyalkylene alkyl ether type nonionic surfactant exceeds 1% by mass, the resist pattern and the seed layer tend to separate or separate, which is not preferable. When the content of the polyoxyalkylene alkyl ether type nonionic surfactant is 0.1% by mass to 0.5% by mass, the surface tension of the acidic degreasing agent is lowered, resulting in the seed layer and the resist material. This is more preferred because it tends to improve the wettability of the acidic degreasing agent to the surface.

A-3. Chloride Ion Source A chloride ion source is a compound that ionizes chloride ions (Cl ⁻ ) into water when contacted with the solvent water. When the acidic degreasing agent contains this chloride ion source, it exhibits an excellent effect of suppressing the erosion of the resist material on the insulating substrate by the acidic degreasing agent.

Examples of chloride ion sources include sodium chloride, hydrochloric acid, copper chloride, ammonium chloride, lithium chloride, potassium chloride, magnesium chloride, calcium chloride, vanadium chloride, manganese chloride, iron chloride, cobalt chloride, nickel chloride, and zinc chloride. mentioned. The acidic degreasing agent of the present application contains at least one or two or more of these compounds.

The content of the chloride ion source in the acidic degreasing agent is 0.001% by mass to 1% by mass in terms of chloride ion concentration. When the content of the chloride ion source is less than 0.001% by mass in terms of chloride ion concentration, the effect of suppressing the corrosion of the resist material on the insulating substrate by the acidic degreasing agent is reduced, and the resist pattern and the It is not preferable because it tends to cause floating or peeling from the seed layer. On the other hand, even if the content of the chloride ion source exceeds 1% by mass as the concentration of chloride ions, the effect of suppressing corrosion of the resist material by the acid degreasing agent is not improved, and it is simply a waste of resources. It is not preferable because

B. Liquid temperature when using the acidic degreasing agent The liquid temperature when using the acidic degreasing agent according to the present application is 15°C to 35°C. If the liquid temperature during use is less than 15°C, the degreasing power of the acidic degreasing agent tends to decrease, which is not preferable. On the other hand, if the liquid temperature exceeds 35° C. during use, the resist pattern and the seed layer tend to separate or separate, which is not preferable. Further, the liquid temperature when the acidic degreasing agent is used is preferably 20°C to 35°C, more preferably 25°C to 35°C. When the liquid temperature of the acidic degreasing agent is 20°C to 35°C, the degreasing effect of the acidic degreasing agent tends to be further improved. This is because the effect can be most improved and the time required for the degreasing treatment can be shortened.

C. Method for Preparing Acidic Degreasing Agent The method for preparing the acidic degreasing agent of the present application is not particularly limited, and can be prepared by a known method. For example, a predetermined amount of sulfuric acid and/or an organic acid, a polyoxyalkylene alkyl ether-type nonionic surfactant, and a chloride ion source are brought into contact with water as a solvent at room temperature, and stirred using a stirrer or the like. Thus, the acidic degreasing agent of the present application can be obtained.

The acidic degreasing agent according to the present application will be specifically described below with reference to examples. However, the invention according to the present application is not limited to these examples.

<Copper clad laminate with resist pattern having electroless copper plating film (seed layer)>
The copper-clad laminate was immersed in an electroless copper plating solution (Melplate CU-390 manufactured by Meltex Co., Ltd.) for 20 minutes at room temperature, washed with water, dried, and plated with 0.3 μm of electroless copper as a seed layer on the surface. A skin was applied. Next, after laminating a dry film resist (LDF725 manufactured by Nikko Materials Co., Ltd., thickness 25 μm) on the copper clad laminate having this electroless copper plating film, a direct exposure device (Co., Ltd. Exposure was performed by irradiating h-line light (wavelength: 405 nm, light intensity: 80 mJ/cm ² ) from a mercury lamp using Fdi-3M manufactured by Oak Manufacturing Co., Ltd.). A developer solution (sodium carbonate aqueous solution with a concentration of 0.75% by mass) at a liquid temperature of 30° C. was sprayed at 0.10 MPa for 27 seconds on the resist material-attached copper-clad laminate having the electroless copper plating film after exposure. By developing the resist material, a "resist patterned copper clad laminate having an electroless copper plating film (seed layer)" with a line/space (L/S) of 5 µm/5 µm was obtained.

<Acidic degreasing agent>
10% by mass of sulfuric acid, which is an acid component, and 0.25% by mass of polyoxyethylene trimethyl nonyl ether (Tergitol TMN-10, manufactured by Dow Chemical Co., Ltd.), which is a polyoxyalkylene alkyl ether type nonionic surfactant. , an acidic degreasing agent having a composition in which the concentration of chloride ions is 0.01% by mass, and the balance is water. The surface tension of this acidic degreasing agent was measured by the Wilhelmy surface tension measurement method. Table 1 shows the composition of the acidic degreasing agent and its surface tension.

<Evaluation of acidic degreasing agent>
The above-mentioned "copper clad laminate with a resist pattern having an electroless copper plating film (seed layer)" is immersed in an acidic degreasing agent at a liquid temperature of 30 ° C. for 10 minutes to perform a degreasing treatment, then washed with water and dried. Floating and twisting of the dry film resist pattern were observed from above using a microscope. FIG. 1(a) shows an image observed with a metallurgical microscope, and Table 1 shows the evaluation results. In Table 1 and Tables 2 to 6, which will be described later, when the dry film resist pattern treated with an acidic degreasing agent is in a good state without floating or twisting, it is indicated as "state of DFR". is "O", and when the dry film resist floats and twists occur, the "state of DFR" is indicated as "x".

Subsequently, a copper Hull cell plate was prepared, a fingerprint was adhered to the plate, and the plate was immersed in an acidic degreasing agent at a liquid temperature of 30°C for 3 minutes. bottom. The evaluation results are shown in Table 1 as "degreasing power (%)".

Furthermore, the same copper-clad laminate as described above was separately prepared and subjected to heat treatment at 120 ° C. for 2 hours to form an oxide film on the surface of the copper foil in the copper-clad laminate. It was immersed in a degreasing agent for 1 minute, and the remaining state of the oxide film was visually observed. Table 1 shows the evaluation results. In Table 1 and Tables 2 to 6 described later, when the oxide film was completely removed from the copper foil surface, the "oxide film removal performance" was "O" and the oxide film remained on the copper foil surface. In this case, the "oxide film removal performance" is indicated as "x".

In Example 2, the test was conducted in the same manner as in Example 1, except that the concentration of sulfuric acid was set to "0.1% by mass". Therefore, the description of the test and evaluation method of Example 2 is omitted. Table 1 and FIG. 1(b) show the composition and evaluation results of the acidic degreasing agent of Example 2, as well as an image observed with a metallographic microscope.

In Example 3, the test was conducted in the same manner as in Example 1, except that the concentration of sulfuric acid in the acidic degreasing agent was changed to "20% by mass". Therefore, the description of test and evaluation methods is omitted. Table 1 and FIG. 1(c) show the composition and evaluation results of the acidic degreasing agent of Example 3, as well as an image observed with a metallographic microscope.

In Example 4, the concentration of polyoxyethylene trimethyl nonyl ether, which is a polyoxyalkylene alkyl ether type nonionic surfactant in the acidic degreasing agent, was changed to "0.01% by mass". A test was conducted in the same manner. Therefore, the description of test and evaluation methods is omitted. Table 1 and FIG. 1(d) show the composition and evaluation results of the acidic degreasing agent of Example 4, as well as an image observed with a metallographic microscope.

In Example 5, the procedure was the same as in Example 1, except that the concentration of polyoxyethylene trimethyl nonyl ether, which is a polyoxyalkylene alkyl ether type nonionic surfactant in the acidic degreasing agent, was changed to "1% by mass." was tested. Therefore, the description of test and evaluation methods is omitted. Table 1 and FIG. 1(e) show the composition and evaluation results of the acidic degreasing agent of Example 5, as well as an image observed with a metallographic microscope.

In Example 6, the polyoxyalkylene alkyl ether type nonionic surfactant in the acidic degreasing agent was changed to "polyoxyethylene polyoxypropylene-2-ethylhexyl ether (Ecosurf EH-9 manufactured by Dow Chemical Co., Ltd.). The test was carried out in the same manner as in Example 1, except that the test and evaluation method are omitted.The composition and evaluation results of the acidic degreasing agent of Example 6 and the metal microscope observation image are shown. , Table 1 and FIG.

In Example 7, the polyoxyalkylene alkyl ether type nonionic surfactant in the acidic degreasing agent was changed to "polyoxyethylene tridecyl ether (Noigen TDS-80 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). The test was carried out in the same manner as in Example 1. Therefore, the description of the test and evaluation method is omitted.The composition and evaluation results of the acidic degreasing agent of Example 7 and the metal microscope observation image are shown in Table 1 and It is shown in FIG.

In Example 8, the test was conducted in the same manner as in Example 1, except that the content of sodium chloride, which is the chloride ion source in the acidic degreasing agent, was changed to "0.001% by mass" in terms of chloride ion concentration. rice field. Therefore, the description of test and evaluation methods is omitted. Table 1 and FIG. 2(a) show the composition and evaluation results of the acidic degreasing agent of Example 8, as well as an image observed with a metallographic microscope.

In Example 9, the test was conducted in the same manner as in Example 1, except that the content of sodium chloride, which is the chloride ion source in the acidic degreasing agent, was changed to "0.1% by mass" in terms of chloride ion concentration. rice field. Therefore, the description of test and evaluation methods is omitted. Table 1 and FIG. 2(b) show the composition and evaluation results of the acidic degreasing agent of Example 9, as well as an image observed with a metallographic microscope.

In Example 10, the test was conducted in the same manner as in Example 1, except that the content of sodium chloride, which is a chloride ion source in the acidic degreasing agent, was changed to "1% by mass" in terms of chloride ion concentration. Therefore, the description of test and evaluation methods is omitted. Table 1 and FIG. 2(c) show the composition and evaluation results of the acidic degreasing agent of Example 10, as well as an image observed with a metallographic microscope.

In Example 11, the test was conducted in the same manner as in Example 1, except that the temperature of the acidic degreasing agent was changed to 15°C. Therefore, the description of test and evaluation methods is omitted. Table 1 and FIG. 2(d) show the composition and evaluation results of the acidic degreasing agent of Example 11, as well as an image observed with a metallographic microscope.

In Example 12, the test was conducted in the same manner as in Example 1, except that the temperature of the acidic degreasing agent was changed to 35°C. Therefore, the description of test and evaluation methods is omitted. Table 1 and FIG. 2(e) show the composition and evaluation results of the acidic degreasing agent of Example 12, as well as the image observed with a metallographic microscope.

Here, Table 1 shows the compositions and evaluation results of the acidic degreasing agents in Examples 1 to 12, which are "forms of acidic degreasing agents containing only sulfuric acid as an acid".

In Example 13, the test was performed in the same manner as in Example 1, except that the acid component in the acidic degreasing agent was changed to "0.1% by mass of glycolic acid" which is an organic acid. Therefore, the description of test and evaluation methods is omitted. Table 2 and FIG. 3(a) show the composition and evaluation results of the acidic degreasing agent of Example 13, as well as an image observed with a metallographic microscope.

In Example 14, the test was performed in the same manner as in Example 1, except that the acid component in the acidic degreasing agent was changed to "20% by mass of glycolic acid" which is an organic acid. Therefore, the description of test and evaluation methods is omitted. Table 2 and FIG. 3(b) show the composition and evaluation results of the acidic degreasing agent of Example 14, as well as an image observed with a metallographic microscope.

In Example 15, the test was performed in the same manner as in Example 1, except that the acid component in the acidic degreasing agent was changed to "5% by mass citric acid" which is an organic acid. Therefore, the description of test and evaluation methods is omitted. Table 2 and FIG. 3(c) show the composition and evaluation results of the acidic degreasing agent of Example 15, as well as an image observed with a metallographic microscope.

In Example 16, the test was performed in the same manner as in Example 1, except that the acid component in the acidic degreasing agent was changed to "5% by mass of methanesulfonic acid" which is an organic acid. Therefore, the description of test and evaluation methods is omitted. Table 2 and FIG. 3(d) show the composition and evaluation results of the acidic degreasing agent of Example 16, as well as the image observed with a metallographic microscope.

Here, Table 2 shows the compositions and evaluation results of the acidic degreasing agents in Examples 13 to 16, which are in the form of acidic degreasing agents containing only an organic acid as an acid.

In Example 17, the same procedure as in Example 1 was performed except that the acid component in the acidic degreasing agent was changed to "0.05% by mass of sulfuric acid" and "0.05% by mass of glycolic acid" which is an organic acid. did the test. Therefore, the description of test and evaluation methods is omitted. Table 3 and FIG. 4(a) show the composition and evaluation results of the acidic degreasing agent of Example 17, as well as an image observed with a metallographic microscope.

In Example 18, the acid component in the acidic degreasing agent was changed to "10% by mass of sulfuric acid" and "0.1% by mass of glycolic acid" which is an organic acid, and the width of the resist pattern was changed to "line/space ( The test was performed in the same manner as in Example 1, except that L/S) was changed to 6 μm/6 μm. Therefore, the description of test and evaluation methods is omitted. Table 3 and FIG. 4(b) show the composition and evaluation results of the acidic degreasing agent of Example 18, as well as an image observed with a metallographic microscope.

Next, in Example 18, the "copper clad with a resist pattern having an electroless copper plating film (seed layer) after degreasing and cleaning obtained by the above-described method (that is, using the acidic degreasing agent of Example 18) Laminate" is immersed in an electrolytic copper plating solution (Lucent Copper PVF manufactured by Meltex Co., Ltd.) for 45 minutes at room temperature at a current density of 2 A / dm ² to form an electrolytic copper plating film on the surface of the electroless copper plating film. A test piece provided with was prepared, and the cross section of this test piece was observed with an electron microscope. FIG. 9(a) shows the cross-sectional observation image. In addition, in FIG. 9(a) and FIG. 9(b) described later, 1 is a "dry film resist pattern", 2 is an "electrolytic copper plating film", 3 is a "seed layer (electroless copper plating film)", 4 , 5 correspond to the "seed layer surface", 5 to the "copper-clad laminate (copper foil on the insulating substrate)", and 6 to the "copper component deposited under the dry film resist pattern".

In Example 19, the test was conducted in the same manner as in Example 1, except that the acid component in the acidic degreasing agent was changed to "10% by mass of sulfuric acid" and "10% by mass of glycolic acid" which is an organic acid. . Therefore, the description of test and evaluation methods is omitted. Table 3 and FIG. 4(c) show the composition and evaluation results of the acidic degreasing agent of Example 19, as well as the image observed with a metallographic microscope.

Here, Table 3 shows the compositions and evaluation results of the acidic degreasing agents in Examples 17 to 19, which are in the form of acidic degreasing agents containing sulfuric acid and an organic acid as acids.

Comparative example

[Comparative Example 1]
In Comparative Example 1, the test was performed in the same manner as in Example 1, except that the concentration of sulfuric acid, which is an acid component in the acidic degreasing agent, was changed to "0.01% by mass". Therefore, the description of test and evaluation methods is omitted. The composition of the acidic degreasing agent of Comparative Example 1, evaluation results, and an image observed with a metallographic microscope are shown in Table 4 and FIG. 5(a). As can be understood from these test results, the acidic degreasing agent of Comparative Example 1, which contained a low amount of sulfuric acid as an acid component, had low degreasing power and insufficient oxide film removal performance.

[Comparative Example 2]
In Comparative Example 2, the test was conducted in the same manner as in Example 1, except that the concentration of sulfuric acid, which is an acid component in the acidic degreasing agent, was changed to "60% by mass". Therefore, the description of test and evaluation methods is omitted. The composition and evaluation results of the acidic degreasing agent of Comparative Example 2 and the image observed with a metallographic microscope are shown in Table 4 and FIG. 5(b). As can be understood from these test results, in Comparative Example 2 in which the content of sulfuric acid, which is an acid component, is high, the surface tension of the acidic degreasing agent is high, and the dry film resist pattern is lifted and twisted.

[Comparative Example 3]
In Comparative Example 3, the concentration of polyoxyethylene trimethyl nonyl ether, which is a polyoxyalkylene alkyl ether type nonionic surfactant in the acidic degreasing agent, was changed to "0.001% by mass", as in Example 1. A test was conducted in the same manner. Therefore, the description of test and evaluation methods is omitted. The composition of the acidic degreasing agent of Comparative Example 3, evaluation results, and an image observed with a metallographic microscope are shown in Table 4 and FIG. 5(c). As can be understood from these test results, in Comparative Example 3, in which the content of the polyoxyalkylene alkyl ether type nonionic surfactant is low, the surface tension of the acidic degreasing agent is high and the degreasing power is low. .

[Comparative Example 4]
In Comparative Example 4, the procedure was the same as in Example 1, except that the concentration of polyoxyethylene trimethyl nonyl ether, which is a polyoxyalkylene alkyl ether type nonionic surfactant, in the acidic degreasing agent was changed to "5% by mass." was tested. Therefore, the description of test and evaluation methods is omitted. The composition of the acidic degreasing agent of Comparative Example 4, evaluation results, and an image observed with a metallographic microscope are shown in Table 4 and FIG. 5(d). As can be understood from these test results, in Comparative Example 4, in which the content of the polyoxyalkylene alkyl ether type nonionic surfactant is high, the dry film resist pattern after treatment with an acidic degreasing agent floats, twists, etc. Occurred.

[Comparative Example 5]
In Comparative Example 5, the nonionic surfactant in the acidic degreasing agent was "EO (ethylene oxide)-PO (propylene oxide) copolymer (Pluronic (registered trademark) L- 44)”, the test was performed in the same manner as in Example 1. Therefore, the description of test and evaluation methods is omitted. Table 4 and FIG. 6(a) show the composition and evaluation results of the acidic degreasing agent of Comparative Example 5, as well as an image observed with a metallographic microscope. As can be understood from these test results, in Comparative Example 5 in which the type of nonionic surfactant is different, the surface tension of the acidic degreasing agent is high and the degreasing power is low.

[Comparative Example 6]
In Comparative Example 6, the nonionic surfactant in the acidic degreasing agent was changed to the same "EO-PO copolymer" as in Comparative Example 5, and the liquid temperature during use of the acidic degreasing agent was changed to "40°C". was tested in the same manner as in Example 1. Therefore, the description of test and evaluation methods is omitted. Table 4 and FIG. 6(b) show the composition and evaluation results of the acidic degreasing agent of Comparative Example 6, as well as the image observed with a metallographic microscope. As can be understood from these test results, in Comparative Example 6, in which the type of nonionic surfactant is different and the liquid temperature during use is high, the surface tension of the acidic degreasing agent is high, the degreasing power is low, and the acidic After the treatment with the degreasing agent, the dry film resist pattern floated and twisted.

[Comparative Example 7]
In Comparative Example 7, the concentration of sulfuric acid, which is the acid component in the acidic degreasing agent, was "5% by mass", the nonionic surfactant was the same "EO-PO copolymer" as in Comparative Example 5, and the liquid when using the acidic degreasing agent The test was performed in the same manner as in Example 1 except that the temperature was changed to "40° C." and the width of the resist pattern was changed to "line/space (L/S) is 6 μm/6 μm". Therefore, the description of test and evaluation methods is omitted. The composition of the acidic degreasing agent of Comparative Example 7, evaluation results, and an image observed with a metallographic microscope are shown in Table 4 and FIG. 6(c). As can be understood from these test results, in Comparative Example 7, which has a different type of nonionic surfactant, does not contain a chloride ion source, and has a high liquid temperature during use, after treatment with an acidic degreasing agent, The dry film resist pattern was lifted and twisted.

Next, in Comparative Example 7, the "copper clad with a resist pattern having an electroless copper plating film (seed layer) after degreasing and cleaning obtained by the above-described method (that is, using the acidic degreasing agent of Comparative Example 7) Laminate", a test piece was obtained by providing an electroless copper plating film on the surface of the electroless copper plating film in the same manner as in Example 18, and the cross section of the test piece was observed with an electron microscope. FIG. 9(b) shows the cross-sectional observation image.

[Comparative Example 8]
In Comparative Example 8, instead of the polyoxyalkylene alkyl ether type nonionic surfactant in the acidic degreasing agent, "polyethylene glycol having a molecular weight of 3400 (PEG4000S manufactured by Sanyo Chemical Industries, Ltd.)" was used. The test was carried out analogously to Example 1. Therefore, the description of test and evaluation methods is omitted. Table 4 and FIG. 6(d) show the composition and evaluation results of the acidic degreasing agent of Comparative Example 8, as well as the image observed with a metallographic microscope. As can be understood from these test results, in Comparative Example 8, in which the type of surfactant is different, the surface tension of the acidic degreasing agent is high and the degreasing power is low.

[Comparative Example 9]
In Comparative Example 9, the test was conducted in the same manner as in Example 1, except that sodium chloride, which is a chloride ion source in the acidic degreasing agent, was not contained. Therefore, the description of test and evaluation methods is omitted. The composition of the acidic degreasing agent of Comparative Example 9, evaluation results, and an image observed with a metallographic microscope are shown in Table 4 and FIG. 6(e). As can be understood from these test results, in Comparative Example 9, which does not contain a chloride ion source, the dry film resist pattern after treatment with an acidic degreasing agent floats, twists, and the like.

[Comparative Example 10]
In Comparative Example 10, the test was conducted in the same manner as in Example 1, except that the temperature of the acidic degreasing agent was changed to "10°C". Therefore, the description of the test and evaluation methods is omitted. The composition of the acidic degreasing agent of Comparative Example 10, the evaluation results, and the image observed with a metallographic microscope are shown in Table 4 and FIG. 6(f). As can be understood from these test results, Comparative Example 10, which had a low liquid temperature during use, had a low degreasing power.

[Comparative Example 11]
In Comparative Example 11, the test was conducted in the same manner as in Example 1, except that the temperature of the acidic degreasing agent was changed to 40°C. Therefore, the description of the test and evaluation methods is omitted. Table 4 and FIG. 6(g) show the composition and evaluation results of the acidic degreasing agent of Comparative Example 11, as well as an image observed with a metallographic microscope. As can be understood from these test results, in Comparative Example 11 in which the liquid temperature during use was high, the dry film resist pattern after treatment with the acidic degreasing agent floated and twisted.

Here, Table 4 shows the compositions and evaluation results of the acidic degreasing agents in Comparative Examples 1 to 11, which are “acidic degreasing agents containing only sulfuric acid as an acid”.

[Comparative Example 12]
In Comparative Example 12, the test was conducted in the same manner as in Example 1, except that the acid component in the acidic degreasing agent was changed to "0.01% by mass of glycolic acid" which is an organic acid. Therefore, the description of test and evaluation methods is omitted. Table 5 and FIG. 7(a) show the composition and evaluation results of the acidic degreasing agent of Comparative Example 12, as well as an image observed with a metallographic microscope. As can be understood from these test results, in Comparative Example 12, in which the content of organic acid is low, the degreasing power of the acidic degreasing agent is low, and the oxide film removal performance is also insufficient.

[Comparative Example 13]
In Comparative Example 13, the test was conducted in the same manner as in Example 1, except that the acid component in the acidic degreasing agent was changed to "30% by mass of glycolic acid" which is an organic acid. Therefore, the description of test and evaluation methods is omitted. Table 5 and FIG. 7(b) show the composition and evaluation results of the acidic degreasing agent of Comparative Example 13, as well as the image observed with a metallographic microscope. As can be understood from these test results, in Comparative Example 13 with a high content of organic acid, the dry film resist pattern after treatment with an acidic degreasing agent floated and twisted.

Here, Table 5 shows the compositions and evaluation results of the acidic degreasing agents in Comparative Examples 12 and 13, which are "acidic degreasing agents containing only an organic acid as an acid."

[Comparative Example 14]
In Comparative Example 14, the same procedure as in Example 1 was performed except that the acid component in the acidic degreasing agent was changed to "0.01% by mass of sulfuric acid" and "0.01% by mass of glycolic acid" which is an organic acid. did the test. Therefore, the description of test and evaluation methods is omitted. Table 6 and FIG. 8(a) show the composition and evaluation results of the acidic degreasing agent of Comparative Example 14, as well as an image observed with a metallographic microscope. As can be understood from these test results, in Comparative Example 14, in which the total content of sulfuric acid and organic acid as acid components is low, the degreasing power of the acidic degreasing agent is low, and the oxide film removal performance is also insufficient. .

[Comparative Example 15]
In Comparative Example 15, the test was conducted in the same manner as in Example 1, except that the acid component in the acidic degreasing agent was changed to "15% by mass of sulfuric acid" and "15% by mass of glycolic acid" which is an organic acid. . Therefore, the description of test and evaluation methods is omitted. Table 6 and FIG. 8(b) show the composition and evaluation results of the acidic degreasing agent of Comparative Example 15, as well as the image observed with a metallographic microscope. As can be understood from these test results, in Comparative Example 15, in which the total content of sulfuric acid and organic acid as acid components is high, the dry film resist pattern after treatment with the acidic degreasing agent floated and twisted.

Here, Table 6 shows the compositions and evaluation results of the acidic degreasing agents in Comparative Examples 14 and 15, which are "acidic degreasing agents containing sulfuric acid and an organic acid as acids."

<Comparison between Examples and Comparative Examples>
According to the test results shown in Tables 1-3 and FIGS. 0.01% by mass to 1% by mass of a polyoxyalkylene alkyl ether type nonionic surfactant, and a chloride ion source containing 0.001% by mass to 1% by mass of chloride ion concentration, and a liquid at the time of use In Examples 1 to 19 where the temperature was 15° C. to 35° C., the surface tension of the acidic degreasing agent was as low as 33.6 mN/m or less, and the dry film resist pattern treated with the acidic degreasing agent floated and twisted. The degreasing power was as high as 70% or more, and the oxide film removing performance was also good.

On the other hand, according to the test results shown in Tables 4 to 6 and FIGS. Any one or more of the content of the ionic surfactant, the chloride ion source, or the liquid temperature during use is outside the preferred numerical range of the invention of the present application, or the composition of the acidic degreasing agent itself is different. , Comparative Examples 1 to 15 resulted in defects in one or more of the surface tension of the acidic degreasing agent, the state of the dry film resist after treatment with the acidic degreasing agent, the degreasing power, and the oxide film removal performance. rice field.

Further, according to the cross-sectional observation images shown in (a) and (b) of FIG. It was confirmed that when the degreasing cleaning was performed as a treatment, an electrolytic copper plating film with a desired shape was obtained without causing lifting or peeling between the resist pattern and the seed layer (electroless copper plating film). On the other hand, the same treatment is performed using an acidic degreasing agent (acidic degreasing agent of Comparative Example 7) that uses a different type of nonionic surfactant, does not contain a chloride ion source, and has a high liquid temperature during use. As a result, lifting or peeling occurs between the resist pattern and the seed layer, resulting in the problem that the copper component gets under the resist pattern and precipitates when copper electroplating is performed.

The acidic degreasing agent of the present application is extremely unlikely to cause lifting or peeling between the resist pattern and the seed layer, and has excellent degreasing power and wettability to the seed layer and the resist material surface, so it is suitable for electrolytic copper pattern plating. It can be preferably used in pretreatment. In particular, it can be suitably used when manufacturing a printed wiring board using an insulating substrate having a seed layer made of copper or a copper alloy.

1 dry film resist pattern 2 electrolytic copper plating film 3 seed layer (electroless copper plating film)
4 Seed layer surface 5 Copper clad laminate (copper foil on insulating substrate)
6 Copper component deposited under the dry film resist pattern

Claims (4)

An acidic degreasing agent used for pretreatment of electrolytic copper pattern plating,
0.1% to 20% by mass of one or more acids selected from the group consisting of sulfuric acid and organic acids, 0.01% to 1% by mass of a polyoxyalkylene alkyl ether type nonionic surfactant, Containing a chloride ion source of 0.001% by mass to 1% by mass in terms of chloride ion concentration,
An acidic degreasing agent characterized by having a liquid temperature of 15°C to 35°C when used. The organic acid is one or more selected from the group consisting of citric acid, formic acid, acetic acid, propionic acid, glycolic acid, malic acid, oxalic acid, succinic acid, maleic acid, methanesulfonic acid, lactic acid, and tartaric acid. 2. The acidic degreasing agent according to 1. The acidic degreasing agent according to claim 1 or 2, wherein the polyoxyalkylene alkyl ether type nonionic surfactant is one or more of the following general formula (1) or general formula (2): .
R ₁ —O—(EO) _m —(AO) _n —H (1)
R ₁ —O—(AO) _n —(EO) _m —H (2)
(In general formulas (1) and (2), R ₁ is a linear or branched alkyl group having 3 to 20 carbon atoms, EO is an oxyethylene group, and m represents the number of repetitions of EO from 2 to is an integer of 20. AO represents PO (oxypropylene group) or BO (oxybutylene group), and n is an integer of 0 to 20 indicating the number of repetitions of AO.) The chloride ion source is the group consisting of sodium chloride, hydrochloric acid, copper chloride, ammonium chloride, lithium chloride, potassium chloride, magnesium chloride, calcium chloride, vanadium chloride, manganese chloride, iron chloride, cobalt chloride, nickel chloride, zinc chloride. The acidic degreasing agent according to any one of claims 1 to 3, which is one or more selected from.

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