JP2011038124A - Metal surface treatment agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal surface treatment agent for roughening a surface of copper or copper alloy to a desired degree with a small amount of etching (amount of etching of 0.5 μm or less), so as to enhance adhesiveness between fine wires of copper or copper alloy and a resin such as a resist and an interlayer insulation material, and to provide a surface treatment method therefor. <P>SOLUTION: This surface treatment method includes roughening the surface of copper or copper alloy to the desired degree with the small amount of etching (amount of etching of 0.5 μm or less) by using the metal surface treatment agent which includes hydrogen peroxide, an inorganic acid, a halogenous ion and triazoles. Then the fine wiring shows excellent adhesiveness between the copper wires and the resin such as the resist and the interlayer insulation material. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a surface treatment agent and a surface treatment method for copper and copper alloy wirings used in the production of printed wiring boards used in electrical and electronic equipment.

  With recent downsizing, weight reduction, and higher functionality of electronic devices, printed wiring boards are strongly required to make copper wiring finer.

  As a method for forming a copper wiring in a conventional printed wiring board, there are generally a subtractive method and a semi-additive method. In the subtractive method, an etching resist layer is formed on a copper surface, and then a resist pattern is formed by exposure and development. Thereafter, unnecessary copper is etched, and the resist is removed to form wiring.

  In the semi-additive method, a metal layer (seed layer) is formed on an insulating material, a plating resist layer is formed on the surface, and then a resist pattern is formed by exposure and development. Thereafter, electrolytic copper plating is applied to remove the resist, and the seed layer is etched to form wiring.

  In the case of the outermost layer wiring, a solder resist or a coverlay is formed on the wiring in order to protect the wiring other than the external connection terminals after the wiring is formed. In the case of a multilayer substrate, an interlayer insulating material is laminated on the wiring formed as described above.

  Resins are generally used for the resists and interlayer insulating materials described above, and machines such as buffing and scrub polishing are used to improve the adhesion between copper wiring and resins such as resists and interlayer insulating materials. The copper surface is roughened by chemical polishing treatment such as treatment or roughening agent.

  As a roughening agent, hydrogen peroxide 1.0-2.5% by weight, sulfuric acid 2.0-2.5% by weight, benzotriazoles 0.2-0.8% by weight, chloride ion 0.0003-0 A technology relating to a surface roughening treatment solution for copper and copper alloy (Patent Document 1) comprising an aqueous solution containing .0015 wt% and having a ratio of chloride ion concentration to benzotriazole concentration of 0.001 to 0.003. Although it is disclosed, there is no description about the adhesion between the copper metal wiring of 15 μm or less and the solder resist, and the adhesion with the solder resist after performing the etching treatment using the treatment liquid described in Patent Document 1 is insufficient. (Comparative Example 3). Etching solution containing hydrogen peroxide, inorganic acid, corrosion inhibitor such as triazole, tetrazole, imidazole, aqueous solution containing halide ion source (Patent Document 2), oxo acid, peroxide, azole and halide (Patent Document 3) ), Adhesion promoting composition containing hydrogen peroxide, inorganic acid, triazole, tetrazole and / or imidazole and surfactant (Patent Document 4), microetching agent containing hydrogen peroxide, sulfuric acid, phenyltetrazole, chloride ion source (Patent Document 5), surface roughening agent (Patent Document 6) containing hydrogen peroxide, sulfuric acid, aminotetrazole, tetrazole compound, phosphonic acid chelating agent, main agent and azoles composed of inorganic acid and copper oxidizing agent A microetching agent comprising an aqueous solution containing an auxiliary agent comprising an etching inhibitor (Patent Document) ) And the like are known.

  With a conventional roughening agent (etching agent), the copper surface is roughened by etching several μm to ensure adhesion between copper and the resist or interlayer insulating material by a physical (anchor) effect. However, in recent years, the copper wiring width has been miniaturized from the conventional 30-50 μm to 15 μm or less, and the conventional roughening agent (etching agent) has a large copper wiring width and the roughness of the copper wiring surface. Is large (the unevenness in the depth direction is large).

Japanese Patent No. 4280171 Japanese Patent No. 3471610 JP-A-10-56263 Japanese Patent No. 2740768 JP 2002-47583 A JP 2009-19270 A JP 2000-282265 A

  The present invention has a surface state with a Ra value (surface roughness) of 0.5 μm or less by etching amount treatment of 0.5 μm or less with respect to a fine copper wiring of 15 μm or less. It is an object of the present invention to provide a metal surface treatment agent and a surface treatment method for roughening the surface of copper or a copper alloy having excellent adhesion to a resin such as a resist or an interlayer insulating material.

  The present inventors have developed a metal surface treatment agent containing hydrogen peroxide, an inorganic acid, a halogen ion, and a triazole, and roughens the surface of copper or copper alloy with a low etching amount. The present inventors have found that the adhesiveness between the resin and a resin such as a resist or an interlayer insulating material is excellent, and have completed the present invention.

That is, the present invention is as follows.
1. A metal surface treating agent for roughening a metal surface of a metal wiring board made of copper or a copper alloy having a wiring width of 15 μm or less with an etching amount of 0.5 μm or less, comprising 0.1 to 1.0% by weight of hydrogen peroxide A metal surface treatment agent comprising 0.3 to 2.0% by weight of an inorganic acid, 0.0001 to 0.0003% by weight of a halogen ion and 0.01 to 0.2% by weight of a triazole.
2. 2. The metal surface treating agent according to item 1, wherein the inorganic acid is at least one inorganic acid selected from nitric acid, sulfuric acid and phosphoric acid.
3. 2. The metal surface treatment agent according to item 1, wherein the halogen ions are chlorine ions and / or bromine ions.
4). 2. The metal surface treating agent according to item 1, wherein the triazole is at least one triazole selected from 1H-benzotriazole, 4-methylbenzotriazole and 5-methylbenzotriazole.
5). The molar ratio of hydrogen peroxide to inorganic acid (hydrogen peroxide / inorganic acid) is 0.95 to 1.20, and the weight ratio of halogen ions to triazoles (halogen ion / triazoles) is 0.002. It is -0.003, The metal surface treating agent of 1st term | claim characterized by the above-mentioned.
6). Contains 0.1 to 1.0% by weight of hydrogen peroxide, 0.3 to 2.0% by weight of inorganic acid, 0.0001 to 0.0003% by weight of halogen ions and 0.01 to 0.2% by weight of triazoles A method of manufacturing a wiring board, wherein the surface roughness (Ra value) of the metal surface of the metal wiring board made of copper or copper alloy having a wiring width of 15 μm or less is set to 0.3 μm or less by using the metal surface treatment agent .
7). 7. The method for manufacturing a wiring board according to item 6, wherein the inorganic acid is at least one inorganic acid selected from nitric acid, sulfuric acid and phosphoric acid.
8). 7. The method for manufacturing a wiring board according to item 6, wherein the halogen ions are chlorine ions and / or bromine ions.
9. 7. The method for producing a wiring board according to item 6, wherein the triazole is at least one triazole selected from 1H-benzotriazole, 4-methylbenzotriazole and 5-methylbenzotriazole.
10. The molar ratio of hydrogen peroxide to inorganic acid (hydrogen peroxide / inorganic acid) is 0.95 to 1.20, and the weight ratio of halogen ions to triazoles (halogen ion / triazoles) is 0.002. The method of manufacturing a wiring board according to item 6, wherein the manufacturing method is .about.0.003.

  The surface treatment agent of the present invention can remarkably improve the adhesion between a fine copper wiring and a resin such as a resist or an interlayer insulating material with a low etching amount (0.5 μm or less), which has been difficult in the past. The above utility value is extremely high.

The electron microscope (SEM) photograph when the copper surface is etched by 0.3 μm with the surface treating agent of Example 1. An electron microscope (SEM) photograph when the copper surface is etched by 0.3 μm with the surface treating agent of Comparative Example 3. An electron microscope (SEM) photograph when the copper surface is etched by 0.3 μm with the surface treating agent of Comparative Example 4.

  The concentration of the hydrogen peroxide of the present invention is 0.1 to 1.0% by weight, preferably 0.1 to 0.9% by weight, more preferably 0.2 to 0.9% by weight. Particularly preferred is 0.2 to 0.8% by weight. If the concentration is less than 0.1% by weight, the oxidation effect is insufficient and a sufficient copper dissolution rate cannot be obtained. If the concentration exceeds 1.0% by weight, no further oxidation effect can be obtained, which is economically preferable. Absent.

  Examples of the inorganic acid include nitric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, hydrochloric acid, boric acid, and the like. Among these, preferred are nitric acid, sulfuric acid, and phosphoric acid. The concentration of the inorganic acid is 0.3 to 2.0% by weight, preferably 0.3 to 1.9% by weight, more preferably 0.4 to 1.9% by weight, and particularly preferably 0.8. 5 to 1.8% by weight. If the concentration is less than 0.3% by weight, a sufficient copper dissolution rate cannot be obtained, and if the concentration exceeds 2.0% by mass, no further improvement in dissolution rate can be obtained, which is economically undesirable.

  The molar ratio of hydrogen peroxide to inorganic acid (hydrogen peroxide / inorganic acid) is 0.90 to 2.00, preferably 0.90 to 1.50, more preferably 0.95 to 1.30. Yes, particularly preferably 0.95 to 1.20.

  Halogen ions have an effect of roughening the surface of copper or copper alloy, and adhesion between copper or copper alloy and a resin such as a resist or an interlayer insulating material is improved. Fluorine ion, chlorine ion, bromine ion and iodine ion can be mentioned. Among these, preferred are chlorine ion and bromine ion. The concentration of the halogen ion is 0.00001 to 0.0003 wt%, preferably 0.00005 to 0.0003 wt%, and particularly preferably 0.0001 to 0.0003 wt%.

  Triazoles have the effect of minutely roughening the surface of copper or a copper alloy when used in combination with halogen ions, and improve the adhesion between the copper or copper alloy and a resin such as a resist or an interlayer insulating material. Among the triazoles, those having a benzene ring are preferable, and among them, 1H-benzotriazole, 4-methylbenzotriazole, and 5-methylbenzotriazole are particularly preferable. The concentration of the triazoles is 0.01 to 0.2% by weight, preferably 0.05 to 0.19% by weight, more preferably 0.1 to 0.19% by weight, and particularly preferably 0. 0.1 to 0.18% by weight.

  The weight ratio of halogen ion to triazole concentration (halogen ion / triazole) is 0.0002 to 0.005, preferably 0.001 to 0.004, more preferably 0.002 to 0.003. It is.

  The etching amount is preferably 0.5 μm or less, preferably 0.4 μm or less, and more preferably 0.3 μm or less.

  The surface roughness (Ra value) of the copper and copper alloy surfaces is preferably 0.5 μm or less, more preferably 0.3 μm from the viewpoint of transmission loss. If the thickness is 0.5 μm or more, there is a high possibility of a problem in transmission loss.

  The etching rate of the copper and copper alloy surfaces varies under various conditions, for example, 0.1 to 5 μm / min, preferably 0.2 to 3 μm, more preferably 30 ° C. under processing conditions. 0.4-2 μm / min. Particularly preferred is 0.5 to 1.5 μm / min.

  The peel strength is preferably 0.7 kgf / cm or more, preferably 0.8 kgf / cm or more, more preferably 0.9 kgf / cm or more, and particularly preferably 1.0 kgf / cm or more.

  Although there is no restriction | limiting in particular regarding the operating temperature of the metal surface treating agent of this invention, It is 20-50 degreeC, Preferably it is 25-40 degreeC, More preferably, it is 25-35 degreeC. The higher the operating temperature, the faster the copper dissolution rate. However, if the temperature exceeds 50 ° C., the decomposition of hydrogen peroxide becomes severe, which is not preferable.

  Although there is no restriction | limiting in particular about the processing method by the metal surface treating agent of this invention, By means, such as immersion and spraying. Further, the processing time is appropriately selected depending on the thickness of the copper or copper alloy to be dissolved.

  The metal surface treating agent of the present invention can be used for various applications. It is useful for improving adhesion with a solder resist, a dry film resist, an electrodeposition resist, a resin of an interlayer insulating material, and a resin as an adhesive.

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples.
-Surface roughness (Ra value) evaluation method: Measured with a laser microscope (OLS3100: manufactured by Olympus). The Ra value is the average value of the heights of the valleys turned back to the peaks with respect to the average line in the measured roughness curve.
-Surface SEM observation: Measured at 30,000 times using Hitachi Electron Microscope S-4700.
-Copper etching amount measuring method: It calculated by the weight method by the following formula | equation.
Etching amount = (weight before treatment−weight after treatment) / (treatment area × 8.92)

Example 1
An electrolytic copper foil (3EC-III manufactured by Mitsui Kinzoku Mining) was treated with an etching solution (CPE-700 manufactured by Mitsubishi Gas Chemical Co., Ltd.) for 1 μm to clean the surface of the copper foil, and then treated with a treating agent having the composition shown in Table 1 to 30 After 0.3 μm etching by immersion at 0 ° C., it was washed with water and dried. The result of SEM observation of the surface state of the treated copper foil is shown in FIG. The surface roughness Ra value measured with a laser microscope was 0.25 μm.
Next, a solder resist (PSR-4000AUS320: manufactured by Taiyo Ink Manufacturing Co., Ltd.) was applied onto the above-described electrolytic copper foil, exposed, developed, and cured to form a solder resist layer. The copper foil peel strength (peel strength) of the obtained laminate was measured according to JISC6481. As a result, it was 1.10 kgf / cm.

Examples 2 and 3
The same procedure as in Example 1 was performed except that the kind of inorganic acid, the kind of halogen, and the kind of triazole were changed from Example 1. The Ra values were 0.20 μm and 0.15 μm, respectively, and the peel strengths were 1.05 kgf / cm and 1.00 kgf / cm.

Comparative Example 1
As a result of carrying out in the same manner as in Example 1 with a halogen-free composition, the Ra value was 0.55 μm and the peel strength was 0.25 kgf / cm.

Comparative Example 2
As a result of carrying out in the same manner as in Example 1 with a composition not containing triazoles, the Ra value was 0.60 μm and the peel strength was 0.20 kgf / cm.

Comparative Example 3
The composition was as described in Example 1 of Patent Document 1 (hydrogen peroxide / sulfuric acid molar ratio was 0.87).
The result of SEM observation of the surface state after etching is shown in FIG. The Ra value was 0.55 μm and the peel strength was 0.55 kgf / cm.
That is, in the etching solution of Comparative Example 3 (Patent Document 1), the copper wiring surface is not densely roughened, so that the adhesion is considered to be insufficient.

Comparative Example 4
The composition was the same as in Example 1 except that the composition was described in Example 4 of Patent Document 2 (halogen ion was 6 ppm).
The result of SEM observation of the surface state after etching is shown in FIG. The Ra value was 0.55 μm and the peel strength was 0.45 kgf / cm.
That is, in the etching solution of Comparative Example 4 (Patent Document 2), the copper wiring surface is not densely roughened, so it is considered that the adhesion is insufficient.

Comparative Example 5
As a result of using the same etching solution (a composition containing no halogen) as in Example 1 of Patent Document 3 and performing the other in the same manner as in Example 1, the Ra value was 0.65 μm and the peel strength was 0.40 kgf / cm.

Comparative Example 6
As a result of using the same etching solution (composition with different azole species) as in Example 1 of Patent Document 5 and performing the other in the same manner as in Example 1, the Ra value was 0.60 μm and the peel strength was 0.40 kgf / cm.

Comparative Example 7
The same etching solution as in Example 1 of Patent Document 6 (composition with different azole species) was used, and the others were carried out in the same manner as in Example 1. As a result, the Ra value was 0.65 μm and the peel strength was 0.45 kgf / cm.

Comparative Example 8
As a result of using the same etching solution (composition without halogen) as in Example 1 of Patent Document 7 and otherwise performing the same as in Example 1, the Ra value was 0.65 μm and the peel strength was 0.45 kgf / cm. Met.

  From the results shown in Table 1, the laminate treated with the surface treatment agent of the present invention has a surface roughness (Ra value) of 0.30 μm or less and a high peel strength (peel strength), which is in close contact with the solder resist. It can be seen that the properties are good.

Claims (10)

  A metal surface treating agent for roughening a metal surface of a metal wiring board made of copper or a copper alloy having a wiring width of 15 μm or less with an etching amount of 0.5 μm or less, comprising 0.1 to 1.0% by weight of hydrogen peroxide A metal surface treatment agent comprising 0.3 to 2.0% by weight of an inorganic acid, 0.0001 to 0.0003% by weight of a halogen ion and 0.01 to 0.2% by weight of a triazole.   The metal surface treating agent according to claim 1, wherein the inorganic acid is at least one inorganic acid selected from nitric acid, sulfuric acid, and phosphoric acid.   The metal surface treatment agent according to claim 1, wherein the halogen ions are chlorine ions and / or bromine ions.   The metal surface treating agent according to claim 1, wherein the triazole is at least one triazole selected from 1H-benzotriazole, 4-methylbenzotriazole and 5-methylbenzotriazole.   The molar ratio of hydrogen peroxide to inorganic acid (hydrogen peroxide / inorganic acid) is 0.95 to 1.20, and the weight ratio of halogen ions to triazoles (halogen ion / triazoles) is 0.002. It is -0.003, The metal surface treating agent of Claim 1 characterized by the above-mentioned.   Contains 0.1 to 1.0% by weight of hydrogen peroxide, 0.3 to 2.0% by weight of inorganic acid, 0.0001 to 0.0003% by weight of halogen ions and 0.01 to 0.2% by weight of triazoles A method of manufacturing a wiring board, wherein the surface roughness (Ra value) of the metal surface of the metal wiring board made of copper or copper alloy having a wiring width of 15 μm or less is set to 0.3 μm or less by using the metal surface treatment agent .   7. The method for manufacturing a wiring board according to item 6, wherein the inorganic acid is at least one inorganic acid selected from nitric acid, sulfuric acid and phosphoric acid.   The method for producing a wiring board according to claim 6, wherein the halogen ions are chlorine ions and / or bromine ions.   The method for producing a wiring board according to claim 6, wherein the triazole is at least one triazole selected from 1H-benzotriazole, 4-methylbenzotriazole and 5-methylbenzotriazole.   The molar ratio of hydrogen peroxide to inorganic acid (hydrogen peroxide / inorganic acid) is 0.95 to 1.20, and the weight ratio of halogen ions to triazoles (halogen ion / triazoles) is 0.002. It is -0.003, The manufacturing method of the wiring board of Claim 6 characterized by the above-mentioned.