JP5813425B2 - Surface treatment liquid for metal or alloy and surface treatment method using the same - Google Patents

Description

  The present invention relates to a surface treatment of a metal or an alloy, and more specifically, a surface treatment solution for a metal or an alloy capable of firmly adhering a resin for laminating, adhering, or photosensitive to the metal or the alloy, and the same. The present invention relates to a surface treatment method using the above.

  Currently, printed boards are manufactured using metals such as copper and alloys such as copper (hereinafter simply referred to as “metals”) and resins for laminating, adhering, and photosensitive.

  When manufacturing such a printed circuit board, first, a photosensitive resin (Dry Film Resist: DFR) is attached to the surface of a metal plate or the like of a laminated board in which multiple layers of metal and resin are stacked, exposed and developed. Then, a DFR circuit mask is formed on the surface of metal or the like. Next, a circuit is formed by dissolving and removing (etching) unnecessary parts of the laminated plate with a chemical.

  If the DFR and the surface of the metal or the like are not firmly adhered at the time of forming the circuit, the DFR floats from the surface of the metal or the like during etching, the circuit is disconnected, and a desired circuit cannot be obtained, resulting in a failure. Therefore, as a method of bringing DFR and the surface of metal into close contact with each other, a method of polishing the surface of metal or the like by mechanical polishing such as buff polishing, brush polishing, scrub polishing or belt sander polishing has been used in the past. .

  However, printed circuit boards are becoming denser, thinner, and thinner, especially for thin objects such as flexible circuit boards, due to the structure of the polishing machine or the dimensions of the substrate due to mechanical force. Decrease in accuracy became a problem, and mechanical polishing could not cope. Therefore, the polishing method has shifted from mechanical polishing to chemical polishing using chemicals.

  On the other hand, even in chemical polishing, the finished color tone is changed due to the roughening of the surface of metal or the like by etching, and it is judged that the appearance is poor by an apparatus (automatic optical inspection apparatus: AOI) that inspects the completion of the circuit. Sometimes it is a problem.

  In addition, when the DFR attachment position on the metal or the like is shifted, the DFR is once removed and removed, and the surface roughening process is performed again. As the roughened state becomes stronger and the unevenness becomes deeper, the reworked substrate becomes difficult to peel off once the DFR is bonded, and the situation where the AOI inspection cannot be passed due to further color change occurs. There is a problem that it ends up.

  By the way, when DFR typified by the semi-additive method is used as a plating resist, the underlying copper seed layer is as thin as 1 μm or less, and etching is roughened because the seed layer is dissolved and removed when etching at the same location. At present, acid degreasing is mostly performed, and high adhesion between DFR and metal cannot be obtained.

  Therefore, there has been a demand for the development of a surface treatment method for metal or the like that can finish the surface of the metal or the like so that DFR or the like can be firmly adhered without etching roughening the surface.

  Such techniques include a treatment liquid containing an azole compound and an acid (Patent Document 1), a treatment liquid containing a specific heterocyclic compound and having a pH of 4 or less (Patent Document 2), and a plurality of aminoazoles. A treatment liquid containing a combination of (Patent Document 3), a treatment liquid containing hydrogen peroxide, phosphoric acid, an amino group-containing azole (Patent Document 4), and the like are known.

  However, in the techniques disclosed in Patent Documents 1 to 3, unevenness occurs due to non-uniform film formation of an azole compound or the like on the surface of a metal or the like, and various conditions (time and temperature) relating to processing Since there is no description, the relationship between the film thickness of the azole compound or the like and the adhesion are not obtained, so the problem of quality deterioration due to the surface treatment described above is caused, and the purpose is to finish the surface so that DFR or the like can be firmly adhered Could not be achieved. Further, even the technique disclosed in Patent Document 4 may cause local copper etching due to the presence of hydrogen peroxide and acid, which may cause problems such as deterioration in quality, and DFR or the like can be firmly adhered. The goal of finishing on the surface could not be achieved.

  In addition, when the above technology is used in the actual printed circuit board manufacturing process, the surface treatment capacity is reduced due to chlorine contained in tap water used in the metal cleaning process and various metal ions carried over from the previous process. There was a problem that it could not withstand repeated use.

JP 2002-321310 A JP 2008-45156 A Japanese Patent No. 3909920 JP 2009-299096 A

  Therefore, the present invention can be finished to a surface capable of firmly adhering a resin for laminating, adhering, photosensitive, etc. without roughening the surface of metal or the like, and manufacturing an actual printed circuit board. Even if it is a case where it uses for a process etc., it makes it a subject to provide surface treatment liquids and surface treatment methods, such as a metal which can endure repeated use.

  As a result of intensive studies to solve the above problems, the present inventor obtained an aqueous solution containing an acid, an azole compound, a metal ion and a halogen ion without laminating the surface of the metal or the like, for laminating, It has been found that the surface can be finished so that the resin for adhesion, for photosensitivity, etc. can be firmly adhered. Further, the present invention has been completed by finding that the above aqueous solution can withstand repeated use even when used in an actual printed circuit board manufacturing process or the like.

  That is, the present invention is a surface treatment solution for a metal or alloy comprising an aqueous solution containing an acid, an azole compound, a metal ion and a halogen ion.

  Moreover, this invention is a surface treatment method of the metal or alloy characterized by making the said surface treatment liquid contact a metal or an alloy.

  The present invention can finish the surface of a metal or an alloy so that the resin for laminating, adhering, and photosensitive can be firmly and uniformly adhered without etching and roughening.

  In addition, since the present invention can be used for reprocessing due to a failure in pasting a resin such as laminating, sticking, or photosensitive to a metal or alloy, resources can be effectively used.

  Furthermore, the present invention can withstand repeated use even when used in an actual printed circuit board manufacturing process or the like, so that resources can be effectively used.

  The surface treatment liquid for metal or alloy of the present invention (hereinafter referred to as “treatment liquid of the present invention”) comprises an aqueous solution containing an acid, an azole compound, metal ions and halogen ions.

  The acid used in the treatment liquid of the present invention is not particularly limited, and examples thereof include inorganic acids such as phosphoric acid and sulfuric acid, and oxo acids such as organic acids such as acetic acid. Among these acids, oxo acids of inorganic acids such as sulfuric acid are preferable. These acids can be used alone or in combination of two or more. Moreover, the compounding quantity of the acid in this invention processing liquid is not specifically limited, For example, it is the quantity which makes pH of this invention processing liquid 4 or less, Preferably it is 2 or less. Specifically, when sulfuric acid is used as the acid, the treatment solution of the present invention may contain 1 g / L to 200 g / L, preferably 3 g / L to 100 g / L, particularly preferably 5 g / L to 50 g / L. .

（式中、Ｒ_１は水素基、メチル基、アミノ基またはニトロ基を表し、Ｒ_２〜Ｒ_５はそれぞれ独立して窒素原子または炭素原子を表す。ここで、Ｒ_２〜Ｒ_５のうちの一つだけが炭素原子を表すときには、当該炭素原子が保持する水素はメチル基またはアミノ基と置換されていてもよい。更に、Ｒ_２とＲ_３および／またはＲ_４とＲ_５は他の炭素環または複素環と共に縮合環を形成してもよい） Examples of the azole compound used in the treatment liquid of the present invention include a 5-membered heterocyclic compound represented by the following formula (1).

(In the formula, R ₁ represents a hydrogen group, a methyl group, an amino group or a nitro group, and R _{2 to} R ₅ each independently represents a nitrogen atom or a carbon atom. Here, of R _{2 to} R ₅ , When only one represents a carbon atom, the hydrogen carried by the carbon atom may be substituted with a methyl group or an amino group, and R ₂ and R ₃ and / or R ₄ and R ₅ may be other carbon atoms. A condensed ring may be formed together with a ring or a heterocyclic ring)

Among the 5-membered heterocyclic compounds represented by the above formula (1), those in which R ₁ represents an amino group are preferable, and 3-aminotetrazole and 5-aminotetrazole are particularly preferable. These azole compounds can be used alone or in combination of two or more. Moreover, the compounding quantity of the azole compound in this invention processing liquid is not specifically limited, For example, 0.01 g / L-saturation, Preferably it is 0.05 g / L-50 g / L, Most preferably, it is 0.1 g / L- 10 g / L.

  The metal ion used in the treatment liquid of the present invention is not particularly limited. For example, ions of the same metal as the metal constituting the metal or alloy to be treated with the treatment liquid of the present invention or ions of a noble metal with respect to the metal If it is. Specifically, in the case where the metal constituting the metal or alloy to be treated with the treatment liquid of the present invention is aluminum, aluminum ions or copper ions may be used, and in the case of copper, copper ions may be used. The compounding amount of the metal ions in the treatment liquid of the present invention is not particularly limited, and is 0.1 g / L to saturation, preferably 0.5 g / L to 40 g / L, particularly preferably 1 g / L to 10 g / L. In the treatment liquid of the present invention, metal ions are necessary for obtaining a uniform film formation of the azole compound on the metal or alloy.

  The halogen ion used in the treatment liquid of the present invention is not particularly limited, and examples thereof include halogen ions such as bromine, iodine, fluorine, and chlorine. Of these halogen ions, chlorine ions are preferred. The compounding amount of the halogen ions in the treatment liquid of the present invention is 0.0001 g / L to 1 g / L, preferably 0.0005 g / L to 0.1 g / L, particularly preferably 0.001 g / L to 0.01 g / L. It is. In the treatment liquid of the present invention, halogen ions are necessary for obtaining a uniform finished surface free from spots of the azole compound.

  Furthermore, in addition to the above components, the treatment liquid of the present invention may contain a surfactant or the like to the extent that the effects of the present invention are not impaired, but it is preferably composed of only the above components.

  The treatment liquid of the present invention containing the above components can be added to water such as ion-exchanged water or the like, or a compound that is a raw material of the above components, for example, metal ions, water-soluble metal compounds, and the like, and halogen ions. It can be adjusted by adding a water-soluble halogen compound or the like and mixing them.

  The treatment liquid of the present invention thus obtained can be subjected to surface treatment by contacting with a metal or alloy.

  Examples of the metal or alloy to be treated with the treatment liquid of the present invention include metals such as iron, aluminum and copper or alloys containing these metals. Among these metals or alloys, copper or a copper alloy is preferable, and copper is particularly preferable.

  In order to bring the treatment liquid of the present invention into contact with a metal or an alloy, a method used for a normal metal surface treatment can be used without any particular limitation. Specific examples include a method in which the treatment liquid of the present invention is placed in a container and a metal or alloy is immersed in the container, and a method in which the treatment liquid of the present invention is placed in a spray container and sprayed on the surface of the metal or alloy. The conditions for these treatments may be appropriately set depending on the type of metal or alloy and the surface conditions. For example, the temperature of the treatment liquid of the present invention may be 10 to 50 ° C., preferably 20 to 40 ° C. The time is 5 seconds to 300 seconds, preferably 10 seconds to 180 seconds, particularly preferably 10 seconds to 120 seconds.

In addition, as a preferable aspect which processes with this invention process liquid, the following surface treatments (1)-(4) in the manufacturing process of the printed wiring board using a copper clad laminated board and DFR are mentioned.
(1) Surface treatment of copper clad laminate on electrolytic copper foil or rolled copper foil to copper and copper alloy (2) Surface treatment on electrolytic copper plating on copper clad laminate (3) Electroless copper plating on resin (4) Surface treatment of sputtered copper on resin

  After the surface treatment is performed on the metal or alloy with the treatment liquid of the present invention as described above, the metal or alloy is thoroughly washed and dried, and thereafter, a resin for laminating, adhesive, photosensitive, etc. is adhered. Just do it.

  In addition, after the surface treatment of the metal or alloy with the treatment liquid of the present invention, the surface of the metal or alloy is not etched, so that the metal or alloy is adhered to a resin for laminating, adhesive, photosensitive, etc. Reworking such as peeling and re-adhering the resin can also be performed.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention concretely, this invention is not limited by a following example etc.

Example 1
Sulfuric acid (H ₂ SO ₄ ) 10 g / L, 5-aminotetrazole 1 g / L, copper sulfate pentahydrate 12 g / L (3 g / L as copper ion (Cu ²⁺ )), sodium chloride 0.0025 g / L ( An aqueous solution containing 0.005 g / L) as a chloride ion (Cl ⁻ ) was prepared and used as a surface treatment solution (pH 1.1). This surface treatment liquid is put into a 200 mL glass beaker, the liquid temperature is kept at 30 ° C., and a test piece (5 cm × 5 cm) of a copper clad laminate (manufactured by Hitachi Chemical Co., Ltd., trade name: MCL-E67) is placed in the liquid. The surface treatment was performed by dipping for 30 seconds. After this surface treatment, the test piece was sufficiently washed with water and dried. The test piece thus obtained was designated as Sample 1. In addition, after the surface treatment, the test piece was replaced with a new one, and the surface treatment was taken as one set, and this was repeated 10 times. The test piece after performing this surface treatment 10 times was designated as Sample 2.

Example 2
A surface treatment solution (pH 1.1) was prepared in the same manner as in Example 1 except that 1H-1,2,3 triazole 1 g / L was used instead of 5-aminotetrazole. Each sample was obtained.

Example 3
A surface treatment solution (pH 1.1) was prepared in the same manner as in Example 1 except that 1 g / L of benzotriazole was used in place of 5-aminotetrazole, and each sample was obtained by subjecting the test piece to surface treatment. It was.

Example 4
A surface treatment solution (pH 1.1) was prepared in the same manner as in Example 1 except that 1-g / L of 3-aminotriazole was used instead of 5-aminotetrazole, and each sample was subjected to surface treatment. Got.

Example 5
A surface treatment solution (pH 1.8) was prepared in the same manner as in Example 1 except that 50 g / L of acetic acid (CH ₃ COOH) was used instead of sulfuric acid. Obtained.

Comparative Example 1
An aqueous solution containing 1 g / L of 5-aminotetrazole was prepared and used as a surface treatment solution (pH 4.0). Using this surface treatment liquid, the sample was surface treated in the same manner as in Example 1 to obtain each sample.

Comparative Example 2
An aqueous solution containing 50 g / L of sulfuric acid and 1 g / L of 5-aminotetrazole was prepared, and this was used as a surface treatment solution (pH 1.1). Using this surface treatment liquid, the sample was surface treated in the same manner as in Example 1 to obtain each sample.

Comparative Example 3
An aqueous solution containing 40 g / L of sulfuric acid and 0.5 g / L of 5-aminotetrazole was prepared and used as a surface treatment solution (pH 1 or less). Using this surface treatment liquid, the sample was surface treated in the same manner as in Example 1 to obtain each sample.

Comparative Example 4
An aqueous solution containing 200 g / L of sulfuric acid and 1 g / L of 5-aminotetrazole was prepared and used as a surface treatment solution (pH 1 or less). Using this surface treatment liquid, the sample was surface treated in the same manner as in Example 1 to obtain each sample.

Comparative Example 5
An aqueous solution containing 5-aminotetrazole 1 g / L and copper 10 g / L was prepared by removing the sulfuric acid, and this was used as a surface treatment solution (pH 2.7). Using this surface treatment liquid, the sample was surface treated in the same manner as in Example 1 to obtain each sample.

Comparative Example 6
An aqueous solution containing 5-aminotetrazole 1 g / L, sulfuric acid 5 g / L, and copper 10 g / L was prepared, and this was used as a surface treatment solution (pH 1.5). Using this surface treatment liquid, the sample was surface treated in the same manner as in Example 1 to obtain each sample.

Comparative Example 7
An aqueous solution containing 5-aminotetrazole 1 g / L, sulfuric acid 10 g / L, and chlorine ions 0.005 g / L was prepared and used as a surface treatment solution (pH 1.1). Using this surface treatment liquid, the sample was surface treated in the same manner as in Example 1 to obtain each sample.

Comparative Example 8
An aqueous solution containing 5-aminotetrazole 1 g / L, sulfuric acid 5 g / L, and copper 40 g / L was prepared, and this was used as a surface treatment solution (pH 1.1). Using this surface treatment liquid, the sample was surface treated in the same manner as in Example 1 to obtain each sample.

Test example 1
The finished appearance of the samples obtained in the above Examples and Comparative Examples was visually examined and evaluated according to the following evaluation criteria.
<Evaluation criteria for finished applications>
(Evaluation) (Content)
○: The sample surface has a uniform finished color tone.
Δ: A part of the sample surface has a non-uniform finished color tone.
×: The sample surface has a non-uniform finish color tone, or precipitates are formed on the sample surface.
occured.

In addition, the pressure-sensitive adhesive tape (polyester tape manufactured by Sekisui Chemical Co., Ltd., trade name: LITHOGRAPHIC) is pressure-bonded to the surface of the sample obtained in the above examples and comparative examples, and then the tape is peeled off and remains on the copper surface of the sample. The transfer state of the glue was visually examined and evaluated according to the following evaluation criteria.
<Evaluation criteria for tape adhesion>
(Evaluation) (Content)
○: The transfer of the tape glue is uniform over the entire surface.
Δ: The transfer of the tape paste is not uniform over the entire surface, and a part thereof is missing.
X: Transfer of the tape paste is not uniform over the entire surface, and part or all of the tape paste is missing.

The following comprehensive judgment was made based on the surface finish of the sample examined above and the tape adhesion.
<Comprehensive evaluation>
(Evaluation) (Content)
○: Both finished appearance and tape adhesion are good.
Δ: Either finished appearance or tape adhesion is not good.
×: Both the finished appearance and the tape adhesion are poor.

  From the results in Table 1, the surface treatment liquids of Examples 1 to 5 according to the present invention satisfy both the finished appearance and the tape adhesion even when used repeatedly 10 times as well as the first. It was.

  On the other hand, the surface treatment liquids of Comparative Examples 1 to 8 which do not contain all of acid, azole compound, metal ion and halogen ion do not satisfy both the finished appearance and the tape adhesion even in the first and tenth times. It was.

Test example 2
A test piece (5 cm × 5 cm) of a copper clad laminate (manufactured by Hitachi Chemical Co., Ltd., trade name: MCL-E67) was immersed in a surface treatment solution prepared in the same manner as in Example 1 for 30 seconds. It was. Thereafter, the amount of copper eluted in the surface treatment liquid was calculated from the weight of the test piece before and after the surface treatment (n = 3).

  The amount of copper eluted in the surface treatment solution averaged -0.003 g, which was within the measurement range error. From this result, it was found that the surface treatment liquid of the present invention did not etch copper.

Example 6
A test piece (5 cm × 5 cm) of a copper clad laminate (manufactured by Hitachi Chemical Co., Ltd., trade name: MCL-E67) was immersed in a surface treatment solution prepared in the same manner as in Example 1 for 120 seconds. It was. After the surface treatment, the test piece was sufficiently washed with water and dried. When the finished appearance and tape adhesion of the test piece after the surface treatment were evaluated in the same manner as in Test Example 1, all were evaluated as “good”.

Example 7
An aluminum foil test piece (5 cm × 5 cm) was immersed in a surface treatment solution prepared in the same manner as in Example 1 for 30 seconds to perform surface treatment. After the surface treatment, the test piece was sufficiently washed with water and dried. The appearance of the test piece after the surface treatment was good.

The treatment liquid of the present invention can be used for a high adhesion finishing process by non-etching / roughening of a metal surface in a manufacturing process of a printed circuit board which is remarkably thinned.

that's all

Claims (7)

Acid, following formula (1)

(In the formula, R ₁ represents a hydrogen group, a methyl group, an amino group or a nitro group, and R _{2 to} R ₅ each independently represents a nitrogen atom or a carbon atom. Here, of R _{2 to} R ₅ , When only one represents a carbon atom, the hydrogen carried by the carbon atom may be substituted with a methyl group or an amino group, and R ₂ and R ₃ and / or R ₄ and R ₅ may be other carbon atoms. A condensed ring may be formed together with a ring or a heterocyclic ring)
The surface treatment liquid for metals or alloys which consists only of the azole compound shown by these , a metal ion, and a halogen ion, and consists of the aqueous solution whose pH is 2 or less. The surface treatment liquid for metal or alloy according to claim 1, wherein the azole compound represented by the formula (1) is 3-aminotetrazole and / or 5-aminotetrazole.   The surface treatment liquid for metal or alloy according to claim 1 or 2, wherein the metal ion is copper.   The surface treatment liquid for metal or alloy according to any one of claims 1 to 3, wherein the halogen ion is a chlorine ion.   The surface treatment liquid for metal or alloy according to any one of claims 1 to 4, which is for surface treatment of copper or copper alloy.   A surface treatment method for a metal or alloy according to any one of claims 1 to 4, wherein the surface treatment solution for metal or alloy is brought into contact with the metal or alloy. 7. The surface treatment method for a metal or alloy according to claim 6, wherein the surface treatment is performed on copper or a copper alloy.