Acidic Degreaser

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]

[0001] The invention of the present application relates to an acidic degreaser used in pretreatment for electrolytic copper pattern plating. [Background technology]

[0002] Generally, when manufacturing a printed wiring board by electrolytic copper pattern plating, a seed layer, which is a thin metal film, is first provided on the surface of an insulating substrate, and then a dry film photoresist (hereinafter referred to as "dry film resist") is applied to the surface of the insulating substrate. 」 or 「 A resist pattern is formed using a resist pattern forming material such as a copper-based resin (hereinafter referred to as "DFR"). This is then electroplated with copper to form a metal film made of copper or a copper alloy, and unnecessary portions where the resist material and seed layer are laminated are removed from the surface of the insulating substrate to obtain a substrate with a conductor circuit pattern (i.e., a printed wiring board).

[0003] Here, as a pretreatment for electrolytic copper pattern plating, the seed layer and the insulating substrate with the resist pattern are degreased, washed, etc. If the solution used for this degreasing treatment is alkaline, the dry film resist may react with the alkaline components in the solution, causing problems such as corrosion, crushing, and peeling. Therefore, a method using an acidic degreaser is adopted. This method is excellent in that it can effectively remove oils and fats remaining on the surface of the seed layer and the resist material without corroding the dry film resist, and can also remove natural oxide films, rust, etc. that have formed on the surface of the seed layer.

[0004] As an example of this type of acidic degreaser, Patent Document 1 discloses "an acidic degreaser containing (A) an acid selected from a divalent carboxylic acid or an alkane sulfonic acid, (B) an acid selected from the group consisting of hydrochloric acid, sulfuric acid, phosphoric acid, and nitric acid, (C) an alkylbenzene sulfonate, and (D) a surfactant having an acetylene bond in the molecule." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2001-89882 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, when a conventional acidic degreaser such as that described in Patent Document 1 is used for pretreatment of electrolytic copper pattern plating, the acidic degreaser may have an unexpected effect on the resist pattern depending on the components and their concentrations, treatment conditions, etc. As a result, floating or peeling occurs between the resist pattern and the seed layer, and when electrolytic copper plating is performed, problems such as metal components made of copper or copper alloys penetrating under the resist material and being precipitated occur. On the other hand, when an acidic degreaser that does not corrode the resist pattern and treatment conditions therefor are used, there is a problem that the degreasing power and wettability to the seed layer surface are insufficient, and a high-quality product cannot be obtained.

[0007] For this reason, those skilled in the art have been in need of an acidic degreaser for use in pretreatment of electrolytic copper pattern plating, which is highly unlikely to cause lifting or peeling between the resist pattern and the seed layer and has excellent degreasing power and wettability to the surface of the seed layer. [Means for solving the problem]

[0008] Therefore, as a result of intensive research, the inventors of the present invention have achieved this object by adopting the following method.

[0009] The acidic degreaser according to the present application is used for pretreatment of copper electroplating patterns, and is characterized in that it contains 0.1% by mass to 20% by mass of one or more acids selected from the group consisting of sulfuric acid and organic acids, 0.01% by mass to 1% by mass of a polyoxyalkylene alkyl ether type nonionic surfactant, and a chloride ion source having a chloride ion concentration of 0.001% by mass to 1% by mass, and has a liquid temperature of 15°C to 35°C during use.

[0010] In the acidic degreasing agent according to the present application, the organic acid is preferably 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.

[0011] In the acidic degreaser according to the present application, the polyoxyalkylene alkyl ether type nonionic surfactant is preferably one or more types represented by the following general formula (1) or general formula (2). R1-O-(EO) m -(AO) n -H (1) R1-O-(AO) n -(EO) m -H (2) (In general formula (1) and general formula (2), R1 is a linear or branched alkyl group having 3 to 20 carbon atoms, EO is an oxyethylene group, 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.)

[0012] In the acidic degreaser according to the present application, the chloride ion source is preferably one or more selected from 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, and zinc chloride. Effect of the Invention

[0013] According to the invention of the present application, it is possible to provide an acidic degreaser for use in pretreatment of electrolytic copper pattern plating, which is extremely unlikely to cause lifting or peeling between the resist pattern and the seed layer, and which has excellent degreasing power and wettability with respect to the seed layer and the surface of the resist material. [Brief description of the drawings]

[0014] [Figure 1]1(a) to 1(g) are metallurgical microscope images taken from above of insulating substrates with seed layers and resist patterns (i.e., copper-clad laminates with resist patterns having electroless copper plating films) in Examples 1 to 7 in which the acidic degreasers of the present application were used. [Diagram 2] 13(a) to 13(e) are metallurgical microscope images of an insulating substrate with a seed layer and a resist pattern, as viewed from above, in Examples 8 to 12, in which the acidic degreaser of the present application was used. [Diagram 3] 14(a) to 14(d) are metallurgical microscope images of an insulating substrate with a seed layer and a resist pattern, as viewed from above, in Examples 13 to 16, in which the acidic degreaser of the present application was used. [Figure 4] 13(a) to 13(c) are metallurgical microscope images of an insulating substrate with a seed layer and a resist pattern, as viewed from above, in Examples 17 to 19, in which the acidic degreaser of the present application was used. [Diagram 5] 14(a) to 14(d) are metallurgical microscope images of the insulating substrate with a seed layer and a resist pattern viewed from above in Comparative Examples 1 to 4, in which acidic degreasers with different concentration conditions were used. [Figure 6] 13(a) to 13(g) are metallurgical microscope images of an insulating substrate with a seed layer and a resist pattern viewed from above in Comparative Examples 5 to 11, which used acidic degreasers with different compositions and / or liquid temperatures during use. [Figure 7] 13(a) and 13(b) are metallurgical microscope images of an insulating substrate with a seed layer and a resist pattern viewed from above in Comparative Example 12 and Comparative Example 13, in which acidic degreasers with different concentration conditions were used. [Figure 8] 13(a) and 13(b) are metallurgical microscope images of an insulating substrate with a seed layer and a resist pattern from above in Comparative Example 14 and Comparative Example 15, in which acidic degreasers with different concentration conditions were used. [Figure 9] 14(a) and 14(b) are cross-sectional observation images of test pieces obtained by electrolytic copper plating on an insulating substrate having a seed layer and a resist pattern in Example 18 using the acidic degreaser of the present application, and in Comparative Example 7 using acidic degreasers having different compositions and liquid temperatures during use. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the acidic degreaser according to the present application will be described with reference to FIGS.

[0016] The acidic degreaser according to the present application is used for pretreatment of electrolytic copper pattern plating, and contains predetermined amounts of "one or more acids selected from the group consisting of sulfuric acid and organic acids," "a polyoxyalkylene alkyl ether type nonionic surfactant," and "a chloride ion source," and has a liquid temperature of 15°C to 35°C when used.

[0017] A. Ingredients of acidic degreasers Each component of the acidic degreaser of the present application will be described below.

[0018] A-1. Acid component The acid component is the main component of the acidic degreaser, and is composed of one or more of sulfuric acid and an organic acid. This acid component has the functions of degreasing and cleaning oil and other contaminants adhering to the seed layer made of copper or a copper alloy on the insulating substrate and the surface of the resist material, and of removing natural oxide films and the like formed on the surface of the seed layer.

[0019] Of 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.

[0020] The content of the acid component in the acidic degreaser 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 dirt such as oil and fat attached to the surface of the seed layer and the resist material on the insulating substrate decreases, and the effect of removing the natural oxide film generated on the surface of the seed layer also tends to decrease, which is not preferable. On the other hand, if the content of the acid component exceeds 20% by mass, the acidic degreaser corrodes the resist material, and lifting or peeling tends to occur between the resist pattern and the seed layer, which is not preferable. The content of the acid component is more preferably 1% by mass to 20% by mass, and further preferably 5% by mass to 15% by mass. If the content of the acid component is 1% by mass to 20% by mass, the effect of degreasing and cleaning dirt such as oil and fat attached to the surface of the seed layer and the resist material tends to be further improved, and if the content of the acid component is 5% by mass to 15% by mass, the effect tends to be most improved and the cost-effectiveness is high. In addition, when the acidic degreasing agent contains two or more types of acid components, the content of the acid components is stated as the total content.

[0021] A-2. Polyoxyalkylene alkyl ether type nonionic surfactants Non-ionic ("Non-ionic 」 or 「 (nonionic) surfactants have the advantage of being excellent in emulsifying and solubilizing power and producing little foaming. Of these nonionic surfactants, the most representative and industrially widely used are polyoxyalkylene alkyl ether type nonionic surfactants. Polyoxyalkylene alkyl ether type nonionic surfactants are ether type surfactants obtained mainly by adding alkylene oxide to alcohol, and have the excellent function of effectively reducing the surface tension of acidic degreasers without the need to add a separate alcohol compound.

[0022] The polyoxyalkylene alkyl ether type nonionic surfactant is preferably one or more of those represented by the following general formula (1) or (2).

[0023] R1-O-(EO) m -(AO) n -H (1) R1-O-(AO) n -(EO) m -H (2) In general formula (1) and general formula (2), R1 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.

[0024] In the above general formula (1) and general formula (2), if the carbon number of R1 is less than 3, the degreasing power of the acidic degreaser tends to decrease, which is not preferred. On the other hand, if the carbon number of R1 exceeds 20, the solubility in water, which is a solvent, tends to decrease, which is not preferred. The carbon number of R1 is more preferably 5 to 18, and even more preferably 7 to 16. If the carbon number of R1 is 5 to 18, the degreasing power and solubility in water of the acidic degreaser tend to be further improved, and if the carbon number of R1 is 7 to 16, this tendency is the highest. Furthermore, if R1 is a branched alkyl group, the degreasing power of the acidic degreaser tends to improve, which is more preferred.

[0025] In the above general formulas (1) and (2), when m is less than 2, the solubility in water as a solvent tends to decrease, which is not preferred. On the other hand, when m exceeds 20, the degreasing power of the acidic degreaser tends to decrease, which is not preferred. And, when m is 4 to 15, the solubility in water and the degreasing power of the acidic degreaser tend to improve, which is more preferred.

[0026] In the above general formulas (1) and (2), it is not preferable that n exceeds 20 because the solubility in water as a solvent tends to decrease, and it is more preferable that n is 0 to 15 because the stability of the acidic degreaser in a high-temperature environment tends to increase.

[0027] The content of the polyoxyalkylene alkyl ether type nonionic surfactant in the acidic degreaser is 0.01% by mass to 1% by mass. If the content of the polyoxyalkylene alkyl ether type nonionic surfactant is less than 0.01% by mass, the surface tension of the acidic degreaser increases, the wettability of the acidic degreaser to the seed layer and the resist material surface decreases, and the degreasing power of the acidic degreaser 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, it is not preferable because lifting or peeling tends to occur between the resist pattern and the seed layer. And, if 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 degreaser decreases, and the wettability of the acidic degreaser to the seed layer and the resist material surface tends to improve, which is more preferable.

[0028] A-3. Chloride ion source The chloride ion source is a material that produces chloride ions (Cl) when it comes into contact with the solvent water. - ) in water. When the acidic degreaser contains this chloride ion source, it has an excellent effect of suppressing the corrosion of the resist material on the insulating substrate by the acidic degreaser.

[0029] Examples of the chloride ion source 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, zinc chloride, etc. The acidic degreaser of the present application contains at least one or more of the group consisting of these compounds.

[0030] The content of the chloride ion source in the acidic degreaser is 0.001% by mass to 1% by mass in terms of chloride ion concentration. If the content of this 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 degreaser is reduced. handThis is undesirable because lifting or peeling tends to occur between the resist pattern and the seed layer. On the other hand, even if the content of this chloride ion source exceeds 1 mass % in terms of chloride ion concentration, the effect of suppressing the corrosion of the resist material by the acidic degreaser is not improved, and it is simply a waste of resources, which is also undesirable.

[0031] B. Temperature of the acidic degreaser when used The liquid temperature of the acidic degreaser according to the present application when used is 15°C to 35°C. If the liquid temperature when used is less than 15°C, the degreasing power of the acidic degreaser tends to decrease, which is not preferable. On the other hand, if the liquid temperature when used exceeds 35°C, floating or peeling tends to occur between the resist pattern and the seed layer, which is not preferable. In addition, the liquid temperature when used is preferably 20°C to 35°C, more preferably 25°C to 35°C. If the liquid temperature when used is 20°C to 35°C, the degreasing and cleaning effect of the acidic degreaser tends to be further improved, and if the liquid temperature when used is 25°C to 35°C, the effect is most improved and the time required for degreasing treatment can be shortened.

[0032] C. Preparation method of acidic degreaser The method for preparing the acidic degreaser of the present application is not particularly limited, and the acidic degreaser of the present application can be prepared by a known method. For example, the acidic degreaser of the present application can be obtained by contacting a predetermined amount of sulfuric acid and / or organic acid, a polyoxyalkylene alkyl ether type nonionic surfactant, and a chloride ion source with water as a solvent at room temperature and stirring the mixture with a stirrer or the like.

[0033] The acidic degreaser according to the present application will be specifically described below with reference to examples, although the invention according to the present application is not limited to these examples. EXAMPLES

[0034] <Copper-clad laminate with resist pattern and electroless copper plating film (seed layer)> The copper-clad laminate was immersed in an electroless copper plating solution (Melplate CU-390, manufactured by Meltex Inc.) at room temperature for 20 minutes, then washed with water and dried, and a 0.3 μm electroless copper plating film was formed on the surface as a seed layer. Next, a dry film resist (LDF725, manufactured by Nikko Materials Co., Ltd., thickness 25 μm) was laminated on the copper-clad laminate with the electroless copper plating film, and light from a mercury lamp (wavelength 405 nm, light intensity 80 mJ / cm) was applied through a photomask using a direct exposure device (Fdi-3M, manufactured by Oak Manufacturing Co., Ltd.). 2 ) was irradiated to perform exposure. After this exposure, a developer solution (aqueous sodium carbonate 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 onto the copper-clad laminate with resist material having the electroless copper plating film, thereby developing the resist material, thereby obtaining a "copper-clad laminate with resist pattern having electroless copper plating film (seed layer)" with a line / space (L / S) of 5 μm / 5 μm.

[0035] <Acidic degreasing agent> An acidic degreaser was prepared with a composition of 10% by mass of sulfuric acid as an acid component, 0.25% by mass of polyoxyethylene trimethylnonyl ether (Tergitol TMN-10 manufactured by Dow Chemical Co.) as a polyoxyalkylene alkyl ether type nonionic surfactant, 0.01% by mass of sodium chloride as a chloride ion source, and the remainder being water. The surface tension of this acidic degreaser was measured by the Wilhelmy surface tension measurement method. Table 1 shows the composition and surface tension of the acidic degreaser.

[0036] <Evaluation of acidic degreasers> The above-mentioned "copper-clad laminate with resist pattern having electroless copper plating film (seed layer)" was degreased by immersing it in an acidic degreaser at a liquid temperature of 30°C for 10 minutes, then washed with water and dried, and the dry film resist pattern was observed from above using a metallurgical microscope for lifting and wrinkling. Figure 1(a) shows the image observed under the metallurgical microscope, and Table 1 shows the evaluation results. In Table 1 and Tables 2 to 6 described below, if the dry film resist pattern treated with the acidic degreaser was in a good condition without lifting or wrinkling, the "DFR condition" was marked with "◯", and if the dry film resist was lifted or wrinkling, the "DFR condition" was marked with "X".

[0037] Next, a copper hull cell plate was prepared, a fingerprint was applied to it, and then it was immersed in an acidic degreaser at 30°C for 3 minutes, rinsed with water, dried, and then visually observed for the remaining fingerprints. The evaluation results are shown in Table 1 as "Degreasing power (%)".

[0038] Furthermore, a copper-clad laminate similar to the above was separately prepared and subjected to a 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, and then the laminate was immersed in an acidic degreaser at a liquid temperature of 30°C for 1 minute, and the state of the remaining oxide film was visually observed. The evaluation results are shown in Table 1. 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 marked with "◯", and when the oxide film remained on the copper foil surface, the "oxide film removal performance" was marked with "X". EXAMPLES

[0039] In Example 2, the test was performed in the same manner as in Example 1, except that the concentration of sulfuric acid was set to "0.1 mass %". Therefore, the test and evaluation method of Example 2 will not be described. The composition of the acidic degreaser of Example 2, the evaluation results, and the metallurgical microscope observation images are shown in Table 1 and FIG. 1(b). EXAMPLES

[0040] In Example 3, the test was performed in the same manner as in Example 1, except that the concentration of sulfuric acid in the acidic degreaser was changed to "20 mass %". Therefore, the description of the test and evaluation method will be omitted. The composition of the acidic degreaser of Example 3, the evaluation results, and the metallurgical microscope observation images are shown in Table 1 and FIG. 1(c). EXAMPLES

[0041] In Example 4, the test was conducted in the same manner 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 degreaser, was changed to "0.01 mass%". Therefore, the description of the test and evaluation method is omitted. The composition of the acidic degreaser of Example 4, the evaluation results, and the metallurgical microscope observation image are shown in Table 1 and FIG. 1(d). EXAMPLES

[0042] In Example 5, the test was conducted in the same manner 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 degreaser, was changed to "1 mass %". Therefore, the description of the test and evaluation method is omitted. The composition of the acidic degreaser of Example 5, the evaluation results, and the metallurgical microscope observation image are shown in Table 1 and FIG. 1(e). EXAMPLES

[0043] In Example 6, the polyoxyalkylene alkyl ether type nonionic surfactant in the acidic degreaser was "polyoxyethylene polyoxypropylene-2-ethylhexyl ether (Ecosurf EH-9 manufactured by The Dow Chemical Company)" 」 The test was carried out in the same manner as in Example 1, except that the composition was changed to the above. Therefore, the description of the test and evaluation methods will be omitted. The composition of the acidic degreaser of Example 6, the evaluation results, and the metallurgical microscope images are shown in Table 1 and FIG. 1(f). EXAMPLES

[0044] In Example 7, the polyoxyalkylene alkyl ether type nonionic surfactant in the acidic degreasing agent was "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, except that the composition was changed to the above. Therefore, the description of the test and evaluation methods will be omitted. The composition of the acidic degreaser of Example 7, the evaluation results, and the metallurgical microscope images are shown in Table 1 and FIG. 1(g). EXAMPLES

[0045] 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 degreaser, was changed to "0.001 mass%" in terms of chloride ion concentration. Therefore, the description of the test and evaluation methods is omitted. The composition of the acidic degreaser of Example 8, the evaluation results, and the metallurgical microscope observation images are shown in Table 1 and FIG. 2(a). EXAMPLES

[0046] 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 degreaser, was changed to "0.1 mass%" in terms of chloride ion concentration. Therefore, the description of the test and evaluation methods is omitted. The composition of the acidic degreaser of Example 9, the evaluation results, and the metallurgical microscope observation images are shown in Table 1 and FIG. 2(b). EXAMPLES

[0047] In Example 10, 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 degreaser, was changed to "1 mass%" in terms of chloride ion concentration. Therefore, the description of the test and evaluation method is omitted. The composition of the acidic degreaser of Example 10, the evaluation results, and the metallurgical microscope observation image are shown in Table 1 and FIG. 2(c). EXAMPLES

[0048] In Example 11, the test was performed in the same manner as in Example 1, except that the temperature of the acidic degreaser during use was changed to "15°C". Therefore, the description of the test and evaluation method will be omitted. The composition of the acidic degreaser in Example 11, the evaluation results, and the metallurgical microscope observation images are shown in Table 1 and FIG. 2(d). EXAMPLES

[0049] In Example 12, the test was performed in the same manner as in Example 1, except that the temperature of the acidic degreaser during use was changed to "35°C". Therefore, the description of the test and evaluation methods will be omitted. The composition of the acidic degreaser in Example 12, the evaluation results, and the metallurgical microscope observation images are shown in Table 1 and FIG. 2(e).

[0050] Table 1 shows the compositions and evaluation results of the acidic degreasers in Examples 1 to 12, which are in the form of "acidic degreasers containing only sulfuric acid as an acid."

[0051] [Table 1] EXAMPLES

[0052] In Example 13, the test was conducted in the same manner as in Example 1, except that the acid component in the acidic degreaser was changed to "0.1 mass% glycolic acid", which is an organic acid. Therefore, the description of the test and evaluation methods is omitted. The composition of the acidic degreaser of Example 13, the evaluation results, and the metallurgical microscope observation images are shown in Table 2 and FIG. 3(a). EXAMPLES

[0053] In Example 14, the test was conducted in the same manner as in Example 1, except that the acid component in the acidic degreaser was changed to "20% by mass glycolic acid", which is an organic acid. Therefore, the description of the test and evaluation methods is omitted. The composition of the acidic degreaser of Example 14, the evaluation results, and the metallurgical microscope observation images are shown in Table 2 and FIG. 3(b). EXAMPLES

[0054] In Example 15, the test was performed in the same manner as in Example 1, except that the acid component in the acidic degreaser was changed to "5% by mass citric acid", which is an organic acid. Therefore, the description of the test and evaluation method is omitted. The composition of the acidic degreaser of Example 15, the evaluation results, and the metallurgical microscope observation image are shown in Table 2 and FIG. 3(c). EXAMPLES

[0055] In Example 16, the test was performed in the same manner as in Example 1, except that the acid component in the acidic degreaser was changed to "5% by mass methanesulfonic acid", which is an organic acid. Therefore, the description of the test and evaluation methods is omitted. The composition of the acidic degreaser of Example 16, the evaluation results, and the metallurgical microscope observation images are shown in Table 2 and FIG. 3(d).

[0056] Table 2 shows the compositions and evaluation results of the acidic degreasers in Examples 13 to 16, which are in the form of "acidic degreasers containing only organic acids as acids."

[0057] [Table 2] EXAMPLES

[0058] In Example 17, the test was performed in the same manner as in Example 1, except that the acid component in the acidic degreaser was changed to "0.05% by mass sulfuric acid" and "0.05% by mass glycolic acid", which is an organic acid. Therefore, the description of the test and evaluation methods is omitted. The composition of the acidic degreaser of Example 17, the evaluation results, and the metallurgical microscope observation images are shown in Table 3 and FIG. 4(a). EXAMPLES

[0059] In Example 18, the acid component in the acidic degreaser was changed to "10% by mass sulfuric acid" and "0.1% by mass glycolic acid" which is an organic acid, and the width of the resist pattern was changed to "line / space (L / S) 6 μm / 6 μm", but the test was performed in the same manner as in Example 1. Therefore, the description of the test and evaluation method is omitted. The composition of the acidic degreaser of Example 18, the evaluation results, and the metallurgical microscope observation image are shown in Table 3 and FIG. 4(b).

[0060] Next, in Example 18, the "copper-clad laminate with resist pattern having electroless copper plating film (seed layer)" obtained by the above-mentioned method (i.e., degreased and washed using the acidic degreaser of Example 18) was immersed in an electrolytic copper plating solution (Lucent Copper PVF manufactured by Meltex Inc.) and subjected to electroplating at room temperature for 45 minutes at 2 A / dm 2 A test piece was prepared in which an electrolytic copper plating film was provided on the surface of an electroless copper plating film at a current density of 1000 sq. m., and the cross section of this test piece was observed using an electron microscope. Figure 9(a) shows the cross-sectional observation image. In Figure 9(a) and Figure 9(b) described below, 1 corresponds to the "dry film resist pattern", 2 to the "electrolytic copper plating film", 3 to the "seed layer (electroless copper plating film)", 4 to the "seed layer surface", 5 to the "copper-clad laminate (copper foil on an insulating substrate)", and 6 to the "copper component that has penetrated and precipitated under the dry film resist pattern". EXAMPLES

[0061] In Example 19, the test was performed in the same manner as in Example 1, except that the acid component in the acidic degreaser was changed to "10% by mass sulfuric acid" and "10% by mass glycolic acid", which is an organic acid. Therefore, the description of the test and evaluation methods is omitted. The composition and evaluation results of the acidic degreaser of Example 19, as well as the metallurgical microscope observation image, are shown in Table 3 and FIG. 4(c).

[0062] Table 3 shows the compositions and evaluation results of the acidic degreasers in Examples 17 to 19, which are in the form of "acidic degreasers containing sulfuric acid and an organic acid as acids."

[0063] [Table 3] Comparative Example

[0064] [Comparative Example 1] In Comparative Example 1, the test was carried out in the same manner as in Example 1, except that the concentration of sulfuric acid, which is the acid component in the acidic degreaser, was changed to "0.01 mass %." Therefore, the description of the test and evaluation methods will be omitted. The composition and evaluation results of the acidic degreaser of Comparative Example 1, as well as the metallurgical microscope observation image, are shown in Table 4 and FIG. 5(a). As can be seen from these test results, the acidic degreaser of Comparative Example 1, which has a low content of sulfuric acid, which is the acid component, had low degreasing power and insufficient oxide film removal performance.

[0065] [Comparative Example 2] In Comparative Example 2, 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 degreaser, was changed to "60 mass %." Therefore, the description of the test and evaluation methods will be omitted. The composition of the acidic degreaser of Comparative Example 2, the evaluation results, and the metallurgical microscope observation images are shown in Table 4 and FIG. 5(b). As can be understood from these test results, in Comparative Example 2, which has a high content of sulfuric acid, which is an acid component, the surface tension of the acidic degreaser was high, and floating and wrinkling occurred on the dry film resist pattern.

[0066] [Comparative Example 3] In Comparative Example 3, the test was performed in the same manner 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 degreaser, was changed to "0.001 mass%". Therefore, the description of the test and evaluation methods will be omitted. The composition of the acidic degreaser of Comparative Example 3, the evaluation results, and the metallurgical microscope observation images are shown in Table 4 and FIG. 5(c). As can be understood from these test results, in Comparative Example 3, which has a low content of polyoxyalkylene alkyl ether type nonionic surfactant, the acidic degreaser had a high surface tension and a low degreasing power.

[0067] [Comparative Example 4] In Comparative Example 4, the test was performed in the same manner 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 degreaser, was changed to "5% by mass." Therefore, the description of the test and evaluation methods will be omitted. The composition of the acidic degreaser of Comparative Example 4, the evaluation results, and the metallurgical microscope observation images are shown in Table 4 and FIG. 5(d). As can be understood from these test results, in Comparative Example 4, which has a high content of a polyoxyalkylene alkyl ether type nonionic surfactant, lifting, twisting, etc. occurred in the dry film resist pattern after treatment with the acidic degreaser.

[0068] [Comparative Example 5] In Comparative Example 5, the test was conducted in the same manner as in Example 1, except that the nonionic surfactant in the acidic degreaser was changed to "EO (ethylene oxide)-PO (propylene oxide) copolymer (Pluronic (registered trademark) L-44 manufactured by ADEKA Corporation)" which is not a polyoxyalkylene alkyl ether type. Therefore, the description of the test and evaluation method is omitted. The composition and evaluation results of the acidic degreaser of Comparative Example 5 and the metallurgical microscope observation image are shown in Table 4 and FIG. 6(a). As can be understood from these test results, in Comparative Example 5, which uses a different type of nonionic surfactant, the surface tension of the acidic degreaser was high and the degreasing power was low.

[0069] [Comparative Example 6] In Comparative Example 6, the nonionic surfactant in the acidic degreaser was changed to the same "EO-PO copolymer" as in Comparative Example 5, and the liquid temperature of the acidic degreaser during use was changed to "40°C." Except for this, the test and evaluation methods are omitted. The composition of the acidic degreaser of Comparative Example 6, the evaluation results, and the metallurgical microscope observation images are shown in Table 4 and FIG. 6(b). As can be understood from these test results, in Comparative Example 6, which uses a different type of nonionic surfactant and has a high liquid temperature during use, the acidic degreaser has a high surface tension and a low degreasing power, and the dry film resist pattern after treatment with the acidic degreaser has lifting, wrinkling, etc.

[0070] [Comparative Example 7] In Comparative Example 7, 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 degreaser, was changed to "5% by mass," the nonionic surfactant was changed to "EO-PO copolymer" the same as in Comparative Example 5, the liquid temperature during use of the acidic degreaser was changed to "40°C," and the width of the resist pattern was changed to "line / space (L / S) of 6 μm / 6 μm." Therefore, the description of the test and evaluation method is omitted. The composition of the acidic degreaser of Comparative Example 7, the evaluation results, and the metallurgical microscope observation image are shown in Table 4 and FIG. 6(c). As can be understood from these test results, 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, caused floating and twisting in the dry film resist pattern after treatment with the acidic degreaser.

[0071] Next, in Comparative Example 7, for the "copper-clad laminate with resist pattern having electroless copper plating film (seed layer)" obtained by the above-mentioned method (i.e., performed using the acidic degreaser of Comparative Example 7) after degreasing and cleaning, a test piece was obtained in which an electrolytic copper plating film was provided on the surface of the electroless copper plating film by the same method as in Example 18, and the cross-section of the test piece was observed by an electron microscope. The cross-sectional observation image is shown in Figure 9(b).

[0072] [Comparative Example 8] In Comparative Example 8, the test was carried out in the same manner as in Example 1, except that "polyethylene glycol having a molecular weight of 3400 (PEG4000S manufactured by Sanyo Chemical Industries, Ltd.)" was used instead of the polyoxyalkylene alkyl ether type nonionic surfactant in the acidic degreaser. Therefore, the description of the test and evaluation method will be omitted. The composition of the acidic degreaser of Comparative Example 8, the evaluation results, and the metallurgical microscope observation image are shown in Table 4 and FIG. 6(d). As can be understood from these test results, in Comparative Example 8, which uses a different type of surfactant, the acidic degreaser had a high surface tension and a low degreasing power.

[0073] [Comparative Example 9] In Comparative Example 9, the test was carried out in the same manner as in Example 1, except that sodium chloride, which is a chloride ion source in the acidic degreaser, was not contained. Therefore, the description of the test and evaluation methods will be omitted. The composition of the acidic degreaser of Comparative Example 9, the evaluation results, and the metallurgical microscope observation images 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, lifting, twisting, etc. occurred in the dry film resist pattern after treatment with the acidic degreaser.

[0074] [Comparative Example 10] In Comparative Example 10, the test was carried out in the same manner as in Example 1, except that the liquid temperature of the acidic degreaser during use was changed to "10°C". Therefore, the description of the test and evaluation methods will be omitted. The composition of the acidic degreaser of Comparative Example 10, the evaluation results, and the metallurgical microscope observation images are shown in Table 4 and FIG. 6(f). As can be seen from these test results, Comparative Example 10, in which the liquid temperature during use was low, had a low degreasing power.

[0075] [Comparative Example 11] In Comparative Example 11, the test was carried out in the same manner as in Example 1, except that the liquid temperature of the acidic degreaser during use was changed to "40°C." Therefore, the description of the test and evaluation methods will be omitted. The composition of the acidic degreaser of Comparative Example 11, the evaluation results, and the metallurgical microscope observation images are shown in Table 4 and FIG. 6(g). As can be seen from these test results, in Comparative Example 11, where the liquid temperature during use was high, lifting, twisting, etc. occurred in the dry film resist pattern after treatment with the acidic degreaser.

[0076] Table 4 shows the compositions and evaluation results of the acidic degreasers in Comparative Examples 1 to 11, which are "acidic degreasers containing only sulfuric acid as an acid."

[0077] [Table 4]

[0078] [Comparative Example 12] In Comparative Example 12, the test was carried out in the same manner as in Example 1, except that the acid component in the acidic degreaser was changed to "0.01% by mass glycolic acid", which is an organic acid. Therefore, the description of the test and evaluation methods will be omitted. The composition of the acidic degreaser of Comparative Example 12, the evaluation results, and the metallurgical microscope observation images are shown in Table 5 and FIG. 7(a). As can be seen from these test results, in Comparative Example 12, which has a low content of organic acid, the degreasing power of the acidic degreaser was low, and the oxide film removal performance was also insufficient.

[0079] [Comparative Example 13] In Comparative Example 13, the test was performed in the same manner as in Example 1, except that the acid component in the acidic degreaser was changed to "30% by mass glycolic acid", which is an organic acid. Therefore, the description of the test and evaluation methods will be omitted. The composition of the acidic degreaser of Comparative Example 13, the evaluation results, and the metallurgical microscope observation images are shown in Table 5 and FIG. 7(b). As can be seen from these test results, in Comparative Example 13, which has a high content of organic acid, lifting, twisting, etc. occurred in the dry film resist pattern after treatment with the acidic degreaser.

[0080] Table 5 shows the compositions and evaluation results of the acidic degreasers in Comparative Examples 12 and 13, which are "acidic degreasers containing only an organic acid as the acid."

[0081] [Table 5]

[0082] [Comparative Example 14] In Comparative Example 14, the test was performed in the same manner as in Example 1, except that the acid components in the acidic degreaser were changed to "0.01% by mass sulfuric acid" and "0.01% by mass glycolic acid", which is an organic acid. Therefore, the description of the test and evaluation methods will be omitted. The composition of the acidic degreaser of Comparative Example 14, the evaluation results, and the metallurgical microscope observation images are shown in Table 6 and FIG. 8(a). As can be seen from these test results, in Comparative Example 14, which has a low total content of the acidic components sulfuric acid and organic acid, the degreasing power of the acidic degreaser was low and the oxide film removal performance was also insufficient.

[0083] [Comparative Example 15] In Comparative Example 15, the test was performed in the same manner as in Example 1, except that the acid components in the acidic degreaser were changed to "15% by mass sulfuric acid" and "15% by mass glycolic acid", which is an organic acid. Therefore, the description of the test and evaluation methods will be omitted. The composition of the acidic degreaser of Comparative Example 15, the evaluation results, and the metallurgical microscope observation images are shown in Table 6 and FIG. 8(b). As can be understood from these test results, Comparative Example 15, which has a high total content of the acid components sulfuric acid and organic acid, caused lifting, wrinkling, and the like in the dry film resist pattern after treatment with the acidic degreaser.

[0084] Table 6 shows the compositions and evaluation results of the acidic degreasers in Comparative Examples 14 and 15, which are "acidic degreasers containing sulfuric acid and an organic acid as acids."

[0085] [Table 6]

[0086] <Comparison between Examples and Comparative Examples> According to the test results shown in Tables 1 to 3 and Figs. 1 to 4, in Examples 1 to 19 in which the acidic degreaser contains 0.1% by mass to 20% by mass of one or more acids selected from the group consisting of sulfuric acid and organic acids, 0.01% by mass to 1% by mass of a polyoxyalkylene alkyl ether type nonionic surfactant, and a chloride ion source at a chloride ion concentration of 0.001% by mass to 1% by mass, and the liquid temperature during use is 15°C to 35°C, the acidic degreaser has a low surface tension of 33.6 mN / m or less, does not float or wrinkle on the dry film resist pattern treated with the acidic degreaser, has a high degreasing power of 70% or more, and has good oxide film removal performance.

[0087] On the other hand, according to the test results shown in Tables 4 to 6 and Figs. 5 to 8, in the acidic degreaser, any one or more of the contents of one or more acids selected from the group consisting of sulfuric acid and organic acids, the polyoxyalkylene alkyl ether type nonionic surfactant, the chloride ion source, or the liquid temperature during use are outside the preferred numerical ranges of the invention of the present application, or the composition of the acidic degreaser itself is different, Comparative Examples 1 to 15 resulted in problems in any one or more of the surface tension of the acidic degreaser, the state of the dry film resist after treatment with the acidic degreaser, the degreasing power, and the oxide film removal performance.

[0088] 9(a) and 9(b), it was confirmed that when the acidic degreaser of the present application (specifically, the acidic degreaser of Example 18) was used to perform degreasing and washing, which is a pretreatment for electrolytic copper pattern plating, an electrolytic copper plating film having a desired shape could be obtained without any floating or peeling between the resist pattern and the seed layer (electroless copper plating film). On the other hand, when the same treatment was performed using an acidic degreaser (the acidic degreaser of Comparative Example 7) that contains a different type of nonionic surfactant, does not contain a chloride ion source, and has a high liquid temperature during use, floating or peeling occurred between the resist pattern and the seed layer, resulting in a defect in that copper components penetrated under the resist pattern and precipitated when electrolytic copper plating was performed. [Industrial Applicability]

[0089] The acidic degreaser of the present application is highly 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 surface of the resist material, and therefore can be suitably used in pretreatment of electrolytic copper pattern plating. In particular, the acidic degreaser 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. [Explanation of symbols]

[0090] 1 Dry film resist pattern 2. Electrolytic copper plating 3 Seed layer (electroless copper plating film) 4. Seed layer surface 5 Copper-clad laminate (copper foil on insulating substrate) 6 Copper components that have penetrated under the dry film resist pattern and precipitated

Claims

1. An acidic degreaser for use in pretreatment of an insulating substrate having a seed layer and a resist pattern for electrolytic copper pattern plating, comprising: The composition comprises 0.1% by mass to 20% by mass of one or more acids selected from the group consisting of sulfuric acid and organic acids, 0.01% by mass to 1% by mass of a polyoxyalkylene alkyl ether type nonionic surfactant, and 0.001% by mass to 1% by mass of a chloride ion source in terms of a chloride ion concentration; An acidic degreaser characterized in that the liquid temperature during use is 15°C to 35°C.

2. 2. The acidic degreaser according to claim 1, wherein the organic acid is at least one 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.

3. 3. The acidic degreaser according to claim 1, wherein the chloride ion source is at least one selected from 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, and zinc chloride.

Images