JP2009019270A - Surface roughening agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface roughening agent which is excellent in adhesion of the surface of Cu or a Cu alloy and a resin and can prevent an oxidation of the surface of Cu after roughened. <P>SOLUTION: The surface roughening agent is used for roughening the surface of Cu or Cu alloy, and includes H<SB>2</SB>SO<SB>4</SB>, H<SB>2</SB>O<SB>2</SB>, 5-aminotetrazol, a tetrazol compound excluding 5-aminotetrazol and a phosphonic-acid based chelate agent. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a surface roughening agent. More specifically, the present invention relates to a surface roughening agent for roughening the surface of copper or an alloy thereof, for example, a surface roughening agent excellent in adhesion to a solder resist or the like.

  When manufacturing a printed wiring board, when laminating a resin on a substrate having a copper surface, in order to improve the adhesion between the copper surface and a resist such as an etching resist, a plating resist, or a solder resist, The roughening of the copper surface is generally performed with a brush.

  In recent years, thinning is required when roughening the copper surface, and chemical polishing using a roughening agent has been proposed as a method suitable for thinning. As such a roughening agent, a roughening agent mainly composed of hydrogen peroxide and sulfuric acid is widely used.

  Etching solution containing oxo acid, peroxide, azole and halide as roughening agent (see, for example, Patent Document 1), sulfuric acid; hydrogen peroxide; triazole, tetrazole and / or imidazole; and adhesion containing surfactant Accelerating composition (for example, see Patent Document 2), oxidizing agent comprising hydrogen peroxide, corrosion inhibitor such as inorganic acid, triazole, tetrazole, imidazole, halide ion source and aqueous solution containing water-soluble polymer (for example, patent Reference 3), surface treatment agent containing hydrogen peroxide, mineral acid, azoles and silver ions (for example, see Patent Document 4), surface containing hydrogen peroxide, mineral acid, azoles and aromatic amine compound A water solution containing a treating agent (for example, see Patent Document 5), an oxidizing agent for copper, an inorganic acid, an azole compound, and an aryl ether compound A surface treatment agent for microetching comprising a copper-containing material roughening agent (for example, see Patent Document 6), an aqueous solution containing hydrogen peroxide, sulfuric acid, 5-amino-1H-tetrazole and cyclohexylamine (for example, a patent) Document 7), a microetching agent (for example, see Patent Document 8) made of an aqueous solution containing a main agent composed of an inorganic acid and an oxidizing agent of copper and an auxiliary composed of an azole and an etching inhibitor are known.

  However, in recent years, since the wiring pattern is becoming thinner, the area where the solder resist and the surface of the wiring pattern are in contact with each other is reduced, and high adhesion is required. Adhesion is not enough.

  Furthermore, the roughened copper surface is very easy to oxidize, and when the copper surface is oxidized, the adhesion to the solder resist is further reduced, so it is required to prevent oxidation of the roughened copper surface. The

JP-A-10-56263 Japanese Patent No. 2740768 Japanese Patent No. 3471610 JP 2002-194573 A JP 2005-133147 A JP 2005-290495 A JP 2004-218021 A JP 2000-282265 A

  This invention is made | formed in view of the said conventional, It is excellent in the adhesiveness of a copper or copper alloy surface and resin, and provides the surface roughening agent for roughening the surface of copper or its alloy. Let it be an issue. Another object of the present invention is to provide a surface roughening agent capable of preventing oxidation of the copper surface after roughening.

  The present invention is a surface roughening agent for roughening a surface made of copper or an alloy thereof, sulfuric acid, hydrogen peroxide, 5-aminotetrazole, tetrazole compounds other than 5-aminotetrazole, and phosphonic acid-based chelates The present invention relates to a surface roughening agent comprising an agent.

  The surface roughening agent of the present invention has an effect that the adhesion between the surface of the copper or copper alloy and the resin is excellent. Moreover, the surface roughening agent of this invention has an effect that the oxidation of the copper surface after roughening can be prevented.

  The concentration of sulfuric acid in the surface roughening agent of the present invention is 3 to 20% by weight from the viewpoint of keeping the copper etching rate within a practical range and suppressing the precipitation of copper sulfate crystals in the surface roughening agent. It is preferable that

  The concentration of hydrogen peroxide in the surface roughening agent of the present invention is such that the etching rate of copper is within a practical range, the storage stability of the surface roughening agent is enhanced, and from the viewpoint of suppressing bumping during use, 2 to 2 It is preferably 10% by weight.

  The concentration of 5-aminotetrazole in the surface roughening agent of the present invention is preferably from the viewpoint of improving the stability of hydrogen peroxide and the solubility in the surface roughening agent, and favorably roughening the surface of copper or its alloy. Is 0.01 to 1.0% by weight, more preferably 0.02 to 0.5% by weight, still more preferably 0.03 to 0.1% by weight.

  Tetrazole compounds other than 5-aminotetrazole (hereinafter referred to as other tetrazole compounds) have the property of roughening the surface in order to increase the adhesion between the surface of copper or its alloy and the resin.

  In the present invention, since 5-aminotetrazole and another tetrazole compound are used in combination, the adhesiveness between the copper or its alloy surface and the resin is improved by the synergistic effect of the combined use of both.

  The molecular weight of the other tetrazole compounds is preferably 180 or less, more preferably 100 or less, from the viewpoint of stably existing in the surface roughening agent of the present invention and forming a preferred roughened shape.

  As other suitable tetrazole compounds, 5-methyltetrazole (molecular weight: 84), 5-ethyltetrazole (molecular weight) is present from the viewpoint of stably present in the surface roughening agent of the present invention and forming a preferred roughened shape. : 98), 5-n-propyltetrazole (molecular weight: 112), 5-phenyltetrazole (molecular weight: 146), 5-toluyltetrazole (molecular weight: 155), 5-aminomethyltetrazole (molecular weight: 87), 5- ( 2-aminophenyl) tetrazole (molecular weight: 161), 5-amino-1-methyltetrazole (molecular weight: 98), 1-phenyl-5-aminotetrazole (molecular weight: 161), 1,5-dimethyltetrazole (molecular weight: 86) And at least one tetrazole compound selected from the group consisting of bistetrazole diammonium (molecular weight: 169) Things. Among these, at least one tetrazole compound selected from the group consisting of 5-methyltetrazole, 5-ethyltetrazole, 5-aminomethyltetrazole, 1-phenyl-5-aminotetrazole and 1,5-dimethyltetrazole) Is more preferable.

  The concentration of the other tetrazole compound in the surface roughening agent of the present invention is preferably 0.003 to 0.3 weight from the viewpoint of increasing the solubility in the surface roughening agent and the adhesion between the copper or its alloy surface and the resin. %, More preferably 0.01 to 0.05% by weight.

  The ratio of the concentration of 5-aminotetrazole and other tetrazole compounds (5-aminotetrazole: tetrazole compounds other than 5-aminotetrazole) is a weight ratio from the viewpoint of enhancing the adhesion between copper or its alloy surface and the resin. , Preferably 1: 1 to 5: 1, more preferably 1.5: 1 to 4: 1. In addition, when using 2 or more types of another tetrazole compound, it is preferable that the total amount of another tetrazole compound shall be 0.003-0.3 weight%.

  The phosphonic acid chelating agent is coordinated to the surface of copper or an alloy thereof by chelating action. At this time, since the coordinating partner is the surface of copper or an alloy thereof, a non-coordinating phosphonic acid group remains as a coordination site in the phosphonic acid chelating agent. Since the remaining phosphonic acid groups are excellent in affinity with the epoxy resin, it is considered that the adhesion between the copper or its alloy surface and the resin is enhanced. Since the surface roughening agent of the present invention contains the phosphonic acid chelating agent, it is suitable for improving the adhesion between the solder resist of epoxy resin and the surface of copper or its alloy.

  Any phosphonic acid chelating agent can be used without particular limitation as long as it exhibits a chelating effect on copper or its alloy.

  The molecular weight of the phosphonic acid chelating agent is preferably 1500 or less, more preferably from the viewpoint of stably present in the surface roughening agent of the present invention and exhibiting an excellent chelating effect on the copper or its alloy surface. 700 or less, more preferably 400 or less, particularly preferably 300 or less.

  Suitable phosphonic acid-based chelating agents include aminotrimethylenephosphonic acid (molecular weight: 299), 1-hydroxyethane-1,1-diphosphonic acid (molecular weight: 206), phosphonobutanetricarboxylic acid (molecular weight: 270), ethylenediamine Tetramethylenephosphonic acid sodium salt (molecular weight: 436), hexamethylenediaminetetramethylenephosphonic acid (molecular weight: 270), diethylenetriaminepentamethylenephosphonic acid (molecular weight: 573), polyaminomethylenephosphonic acid (molecular weight: 10,000 or more) and bishexamethylene And at least one phosphonic acid chelating agent selected from the group consisting of triaminepentamethylenephosphonic acid (molecular weight: 685). Among these, aminotrimethylenephosphonic acid (molecular weight: 299), 1-hydroxyethane-1,1-diphosphonic acid (molecular weight: 206), phosphonobutanetricarboxylic acid (molecular weight: 270), and hexamethylenediaminetetramethylenephosphone. More preferred is at least one phosphonic acid chelating agent selected from the group consisting of acids (molecular weight: 270).

The concentration of the phosphonic acid chelating agent in the surface roughening agent of the present invention is preferably 0.05 to 2.1, from the viewpoint of enhancing the stability of hydrogen peroxide and enhancing the adhesion between the copper or its alloy surface and the resin. It is 0% by weight, more preferably 0.1 to 1.0% by weight.

  If necessary, a hydrogen peroxide stabilizer, an antifoaming agent, a surfactant and the like can be appropriately added to the surface roughening agent of the present invention.

  In addition, halogen ions such as chlorine ions may be added to the surface roughening agent of the present invention in order to adjust the roughening shape and the etching rate. The concentration of halogen ions in the surface roughening agent of the present invention is preferably 1 to 60 ppm, more preferably 5 to 40 ppm from the viewpoint of sufficiently roughening the copper surface and increasing the etching rate.

  As a method of using the surface roughening agent of the present invention, for example, a method of spraying the surface roughening agent of the present invention on the surface made of copper or an alloy thereof, or the surface roughening agent of the present invention is made of copper or a copper alloy. The method etc. which immerse the base material which has a surface are mentioned.

  The amount by which the surface made of copper or an alloy thereof is etched by the surface roughening agent of the present invention (hereinafter referred to as etching amount) can be adjusted by the composition of the surface roughening agent of the present invention, its temperature, etching time, etc. it can. The temperature when using the surface roughening agent of the present invention is usually about 20 to 35 ° C., and the time when etching using the surface roughening agent of the present invention varies depending on the amount of etching, so it is generally Although it cannot be determined, it may be about 10 to 60 seconds.

  The etching amount may be set as appropriate according to the type of resin to be brought into contact with the surface of the material to be etched, etc., but the copper or copper alloy surface is roughened well, and the copper or its alloy surface and resin From the viewpoint of improving the adhesiveness, it is usually preferably about 0.1 to 2.0 μm, more preferably about 0.2 to 1.0 μm.

  In addition, the etching amount as used in this specification is the etching depth calculated from the weight change before and after etching of the material to be etched, the surface area of the copper or copper alloy surface, and the density of copper or copper alloy. Say.

  The surface roughening agent of the present invention can be used for various applications. Examples of the application include prepreg, solder resist, dry film resist, electrodeposition resist, adhesive and the like. The surface roughening agent of the present invention is useful for improving the adhesion between the surface of copper or an alloy thereof and the interlayer insulating resin of the build-up printed wiring board, and is used for the surface treatment of the lead frame. Or it is useful also in improving the adhesiveness of the alloy surface and adhesive sealing resin.

  Examples of the copper alloy include one containing 50 wt% or more of copper and 50 wt% or less of a metal other than copper such as tin, gold, silver, and aluminum as the other metal.

  Examples of the resin include phenol resin, epoxy resin, heat-resistant epoxy resin, polyimide, bismaleimide / triazine resin, polyphenylene ether, acrylic resin, ultraviolet curable epoxy resin, and ultraviolet curable acrylic resin. Is not limited to such examples. In these, since it is excellent in adhesiveness with the surface of copper or its alloy, epoxy resins, such as an epoxy resin, a heat-resistant epoxy resin, and an ultraviolet curable epoxy resin, are preferable.

  Next, the present invention will be described in more detail based on examples. However, the present invention is not limited to such examples.

Examples 1-10 and Comparative Examples 1-7
A double-sided copper-clad laminate in which a 18 μm thick copper foil is pasted on both sides of a glass epoxy substrate (manufactured by Hitachi Chemical Co., Ltd., product number: GEA-67N, thickness: 1.6 mm) is prepared. Electrolytic copper plating was further performed on both surfaces so that the thickness of the plating layer was 20 μm, and the test substrate was cut into a length of 8.5 cm and a width of 11.0 cm.

  After this glass substrate was etched with a surface roughening agent having the composition shown in Table 1 at an etching amount of 0.5 μm, a solder resist (manufactured by Taiyo Ink Manufacturing Co., Ltd., product number: PSR4000Z26) was thickened. After printing to a thickness of 15 to 30 μm, the film was exposed and developed under normal conditions.

  Next, as physical properties of each test substrate, adhesion and antioxidant properties were examined according to the following methods. The results are shown in Table 1.

(1) Adhesiveness Each test substrate was cross-cut in a 1 mm × 1 mm grid according to JIS K5600-5-6, immersed in a 10% by weight hydrochloric acid aqueous solution at room temperature for 10 minutes, washed with water, dried, and JIS K5600- A tape peel test was performed according to 5-6, and the adhesion was evaluated based on the following evaluation criteria. The results are shown in Table 1.

[Evaluation criteria for adhesion]
A: Solder resist film does not adhere to the adhesive tape at all B: Solder resist film slightly adheres to the adhesive tape C: Solder resist film adheres to the adhesive tape in large quantities

  The tape peel test is a test in which the adhesive tape is attached to the solder resist film, peeled off, and the adhesion is measured by checking whether the peeled piece of the solder resist film is attached to the adhesive tape side. It is better that no film adheres.

(2) Antioxidant Each test substrate after etching a glass epoxy base material with an etching amount of 0.5 μm using a surface roughening agent having the composition shown in Table 1 is placed in a thermostatic bath at 40 ° C. and a relative humidity of 95%. The surface after 30 minutes had passed was observed with a metallographic microscope and evaluated based on the following evaluation criteria.

[Evaluation criteria for antioxidant properties]
A: No change in color (not oxidized)
B: What was partially changed to light brown (partially oxidized)
C: The color is completely brown (oxidation is progressing entirely)

  From the results shown in Table 1, since the surface roughening agent obtained in each example of the present invention contains 5-aminotetrazole, other 5-aminotetrazole compounds and a phosphonic acid chelating agent, It can be seen that the adhesion between the surface of the copper or copper alloy and the resin is excellent.

  Next, as an example in which the evaluation was A, the optical photograph (magnification: 5 times) of the pressure-sensitive adhesive tape in Example 1 is shown in FIG. An optical photograph (magnification: 5 times) of the tape is shown in FIG. 2, and as an example where the evaluation was C, an optical photograph (magnification: 5 times) of the adhesive tape in Comparative Example 1 is shown in FIG.

  As shown in FIGS. 1 to 3, in Comparative Example 1, a large amount of solder resist film is adhered to the adhesive tape, but in Example 4, the solder resist film is only slightly adhered to the adhesive tape. In Example 1, it can be seen that the solder resist film does not adhere to the adhesive tape at all.

  In addition, as an example in which the evaluation was A for the antioxidant property, an optical photograph (magnification: 1 time) of the test substrate surface after the processing in Example 1 is shown in FIG. An optical photograph of the test substrate surface after treatment in Example 4 (magnification: 1 ×) is shown in FIG. 5, and as an example in which the evaluation was C, an optical photograph of the surface of the test substrate after treatment in Comparative Example 1 (magnification: 1 ×) ) Is shown in FIG.

  As shown in FIGS. 4 to 6, in Comparative Example 1, the test substrate after the treatment was entirely changed to brown so that unevenness was observed on the surface, but in Example 4, the test after the treatment was performed. The surface of the substrate is only partially changed to light brown, and in Example 1, it can be seen that there is almost no color change on the surface of the test substrate after processing.

As described above, it can be seen that the surface roughening agent of the present invention can impart high adhesion between the copper or copper alloy surface and the resin. Moreover, it turns out that the surface roughening agent of this invention can prevent the oxidation of the copper surface after roughening.

It is a figure which shows the optical photograph of the adhesive tape after the adhesiveness test in Example 1 of this invention. It is a figure which shows the optical photograph of the adhesive tape after the adhesiveness test in Example 4 of this invention. It is a figure which shows the optical photograph of the adhesive tape after the adhesiveness test in the comparative example 1. FIG. It is a figure which shows the optical photograph of the test substrate surface after the antioxidant test in Example 1 of this invention. It is a figure which shows the optical photograph of the test substrate surface after the antioxidant test in Example 4 of this invention. It is a figure which shows the optical photograph of the test substrate surface after the antioxidant test in the comparative example 1. FIG.

Claims (9)

  A surface roughening agent for roughening a surface made of copper or an alloy thereof, containing sulfuric acid, hydrogen peroxide, 5-aminotetrazole, tetrazole compounds other than 5-aminotetrazole, and a phosphonic acid chelating agent A surface roughening agent characterized by that.   Tetrazole compounds other than 5-aminotetrazole include 5-methyltetrazole, 5-ethyltetrazole, 5-n-propyltetrazole, 5-phenyltetrazole, 5-toluyltetrazole, 5-aminomethyltetrazole, 5- (2-aminophenyl) 2) At least one tetrazole compound selected from the group consisting of tetrazole, 5-amino-1-methyltetrazole, 1-phenyl-5-aminotetrazole, 1,5-dimethyltetrazole and bistetrazole diammonium. The surface roughening agent according to 1.   Phosphonic acid-based chelating agents are aminotrimethylenephosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid, phosphonobutanetricarboxylic acid, ethylenediaminetetramethylenephosphonic acid sodium salt, hexamethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylene The surface roughening agent according to claim 1 or 2, which is at least one phosphonic acid chelating agent selected from the group consisting of phosphonic acid, polyaminomethylenephosphonic acid and bishexamethylenetriaminepentamethylenephosphonic acid.   The surface roughening agent according to any one of claims 1 to 3, wherein the concentration of sulfuric acid is 3 to 20% by weight.   The surface roughening agent according to any one of claims 1 to 4, wherein the concentration of hydrogen peroxide is 2 to 10% by weight.   The surface roughening agent according to any one of claims 1 to 5, wherein the concentration of 5-aminotetrazole is 0.01 to 1.0% by weight.   The surface roughening agent according to any one of claims 1 to 6, wherein the concentration of a tetrazole compound other than 5-aminotetrazole is 0.003 to 0.3% by weight.   The ratio of the concentration of 5-aminotetrazole to a tetrazole compound other than 5-aminotetrazole (5-aminotetrazole: tetrazole compound other than 5-aminotetrazole) is 1: 1 to 5: 1 (weight ratio). The surface roughening agent in any one of 1-7. The surface roughening agent according to any one of claims 1 to 8, wherein the concentration of the phosphonic acid chelating agent is 0.05 to 2.0% by weight.