JP2011080131A - Metal surface treatment method and method for manufacturing wiring board - Google Patents

Abstract

A 15μm following fine copper or the surface of the copper alloy wiring, by Ra value low etching amount (hereinafter etching amount 0.5 [mu] m) is roughened to the extent of 0.5 [mu] m or less, and fine copper wiring Provided is a method for treating a wiring board having a surface with excellent adhesion to a resin such as a resist or an interlayer insulating material.
Treatment with a first treatment liquid containing an inorganic acid such as hydrogen peroxide and nitric acid, a halogen ion, and triazole, followed by treatment with a second treatment liquid containing hydrogen peroxide and an inorganic acid, A method for treating a wiring board, which is treated with a third treatment liquid containing a silane compound.
[Selection] Figure 1

Description

  The present invention relates to a surface treatment method for copper and copper alloy wiring used in the manufacture of printed wiring boards used in electrical and electronic equipment and the like, and a method for manufacturing a wiring board.

  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 the conventional printed wiring board, generally there is a subtractive method and 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 a multilayer substrate, an interlayer insulating material is laminated on the wiring formed above. In addition, a solder resist or a coverlay is formed on the wiring in order to protect the wiring other than the external connection terminals after forming the wiring on the outermost layer wiring.

  In general, resin is used for the interlayer insulating material and resist, and mechanical processing and roughening such as buffing and scrub polishing are performed to improve the adhesion between the copper wiring and the resin such as the interlayer insulating material and resist. The copper surface is roughened by a chemical polishing process such as an agent.

  As a roughening agent, a technique relating to a surface roughening solution of copper and a copper alloy containing hydrogen peroxide, sulfuric acid, benzotriazoles, chloride ions (Patent Document 1) is disclosed, but copper metal of 15 μm or less is disclosed. There was no description regarding the adhesion between the wiring and the solder resist, and the adhesion with the interlayer insulating resin after performing the etching treatment using the treatment liquid described in Patent Document 1 was insufficient (Comparative Example 5). 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 an interlayer insulating material or resist by a physical (anchor) effect. However, in recent years, the copper wiring width has been reduced from the conventional 30-50 μm to 15 μm or less, and the conventional roughening agent (etching agent) makes the copper wiring narrow and difficult to form the wiring (wiring of the wiring). (Disappearance) 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 an Ra value (surface roughness) of 0.5 μm or less by etching with an etching amount of 0.5 μm or less on a fine copper wiring of 15 μm or less, and the copper wiring and interlayer insulation It is an object of the present invention to provide a surface treatment method for roughening a copper or copper alloy surface excellent in adhesion to a resin such as a material or a solder resist, and a method for manufacturing a wiring board.

  In the present invention, the first treatment liquid composed of hydrogen peroxide, an inorganic acid, a halogen ion, and a triazole, the second treatment liquid composed of hydrogen peroxide, an inorganic acid, and the third treatment liquid composed of a silane compound, Alternatively, by roughening the surface of the copper alloy with a low etching amount, it was found that the adhesion between the copper wiring and a resin such as an interlayer insulating material or a solder resist is excellent in a fine copper wiring, and the present invention has been completed. .

That is, the present invention is as follows.
1. A method of roughening the metal surface of the metal wiring board comprising a wiring width 15μm or less copper or a copper alloy, 0.1 to 1 wt% hydrogen peroxide, 0.3 to 2 wt% inorganic acids, halogen ions 0 after treatment with a first treatment solution containing .0001～0.0003 wt% and triazoles 0.01-0.2 wt%, 30 wt% hydrogen peroxide, an inorganic acid from 0.001 to 0 The metal surface treatment method is characterized by treating the surface of the metal wiring with a second treatment liquid containing 1% by mass.
2. Furthermore, the metal surface treatment method characterized by processing the surface of this metal wiring using the 3rd process liquid characterized by containing 0.1-5 mass% of silane compounds.
3. 3. The metal surface treatment method according to item 1 or 2, wherein the inorganic acid is at least one inorganic acid selected from nitric acid, sulfuric acid, and phosphoric acid.
4). 3. The metal surface treatment method according to item 1 or 2, wherein the halogen ions are chlorine ions or bromine ions.
5). 3. The metal surface treatment according to item 1 or 2, wherein the triazole is at least one triazole selected from 1H-benzotriazole, 4-methylbenzotriazole and 5-methylbenzotriazole. Method.
6). Metal surface treatment method according to claim 1 or 2, wherein, wherein the weight ratio of the halide ion and triazoles (halogen ions / triazoles) is from 0.0002 to 0.003.
7). Silane compound, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl)) - 3-aminopropyltrimethoxysilane, N-2- (aminoethyl)) - 3- metal surface treatment method according to paragraph 2, characterized in that at least one selected from 3-aminopropyl dimethoxysilane - aminopropyltriethoxysilane and N-2- (aminoethyl)).
8). Hydrogen peroxide 0.1 to 1 wt%, 0.3 to 2 wt% inorganic acids, the first processing containing a silver ion from 0.0001 to 0.0003 wt% and triazoles 0.01-0.2 wt% solution was treated with 1 to 30 wt% of hydrogen peroxide, treated with a second treatment solution containing 0.001 to 0.1 wt% inorganic acid, silane compounds 0.1 to 5 mass% of using a third processing liquid characterized by containing the following wiring width 15μm copper or metal wiring board comprising a copper alloy surface roughness of the metal surface (Ra value) of the following metal wiring board 0.5μm Production method.
9. 9. The method for manufacturing a wiring board according to item 8, wherein the inorganic acid is at least one selected from nitric acid, sulfuric acid, and phosphoric acid.
10. 9. The method for manufacturing a wiring board according to item 8, wherein the halogen ions are at least one selected from chlorine ions or bromine ions.
11. The method for producing a wiring board according to item 8, wherein the triazole is at least one selected from 1H-benzotriazole, 4-methylbenzotriazole, and 5-methylbenzotriazole.
12 A method for manufacturing a wiring board according to paragraph 8 in which the mass ratio of the concentration of halogen ions and triazoles (halogen ions / triazoles) is characterized in that it is a 0.0002-.003.
13. Silane compound, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl)) - 3-aminopropyltrimethoxysilane, N-2- (aminoethyl)) - 3- Item 9. The method for manufacturing a wiring board according to Item 8, wherein the method is at least one selected from aminopropyltriethoxysilane and N-2- (aminoethyl))-3-aminopropylmethyldimethoxysilane.

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

The electron microscope (SEM) photograph when the copper surface is etched by 0.3 μm with the surface treatment liquid of Example 1. An electron microscope (SEM) photograph when the copper surface is etched by 0.3 μm with the surface treatment solution of Comparative Example 5. An electron microscope (SEM) photograph when the copper surface is etched by 0.3 μm with the surface treatment liquid of Comparative Example 6.

  The concentration of hydrogen peroxide in the first treatment liquid of the present invention is 0.1 to 1% by mass, preferably 0.1 to 0.9% by mass, and more preferably 0.2 to 0.9% by mass. %, Particularly preferably 0.2 to 0.8% by mass. If the concentration is less than 0.1% by mass, the oxidation effect is insufficient and a sufficient copper dissolution rate cannot be obtained. If the concentration exceeds 1% by mass, the dissolution rate becomes too fast and a dense roughened surface is obtained. This is not preferable.

  Examples of the inorganic acid in the first treatment liquid include nitric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, hydrochloric acid, and boric acid. Among these, nitric acid, sulfuric acid, and phosphoric acid are preferable. The concentration of the inorganic acid is 0.3 to 2% by mass, preferably 0.3 to 1.9% by mass, more preferably 0.4 to 1.9% by mass, and particularly preferably 0.5 to 1.8% by mass. If the concentration is less than 0.3% by mass, a sufficient copper dissolution rate cannot be obtained, and if the concentration exceeds 2% by mass, the dissolution rate becomes too fast and a dense roughened surface cannot be obtained.

  The molar ratio of hydrogen peroxide to inorganic acid (hydrogen peroxide / inorganic acid) in the first treatment liquid is 0.90 to 2.00, preferably 0.90 to 1.50, more preferably 0.95. -1.30, particularly preferably 0.95-1.20. When the molar ratio is less than 0.90 and more than 2.00, an etching treatment of 0.5 μm or less is not preferable because a dense roughened surface cannot be obtained.

  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 density | concentration of a halogen ion is 0.00001-0.0003 mass%, Preferably it is 0.00005-0.0003 mass%, Most preferably, it is 0.0001-0.0003 mass%.

  Triazoles, when used in combination with halogen ions, have the effect of finely roughening the surface of copper or copper alloy, and improve the adhesion between copper or copper alloy and resins such as interlayer insulating materials and resists. 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 mass, preferably 0.05 to 0.19% by mass, more preferably 0.1 to 0.19% by mass, and particularly preferably 0. 0.1 to 0.18% by mass.

  The mass ratio of the concentration of halogen ions to triazoles (halogen ions / triazoles) is 0.0002 to 0.005, preferably 0.001 to 0.004, more preferably 0.002 to 0.003. It is. When the mass ratio is less than 0.0002 and more than 0.005, a dense roughened surface cannot be obtained when an etching treatment of 0.5 μm or less is performed, which is not preferable.

  The concentration of hydrogen peroxide in the second treatment liquid is 0.1 to 30% by mass, preferably 1 to 20% by mass, and more preferably 5 to 10% by mass. When the concentration is less than 0.1% by mass, the oxidation effect is insufficient, and when the concentration exceeds 30% by mass, no further oxidation effect is obtained, which is economically undesirable.

  Examples of the inorganic acid in the second treatment liquid include nitric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, hydrochloric acid, and boric acid. Among these, nitric acid, sulfuric acid, and phosphoric acid are preferable. The density | concentration of an inorganic acid is 0.001-0.1 mass%, Preferably it is 0.003-0.05 mass%, More preferably, it is 0.005-0.01 mass%. If the concentration is less than 0.001% by mass, a sufficient copper dissolution rate cannot be obtained, and if the concentration exceeds 0.1% by mass, the dissolution rate becomes too fast and a dense roughened surface cannot be obtained.

  The silane compound contained in the third treatment liquid chemically improves the adhesion between copper or a copper alloy and a resin such as an interlayer insulating material or a resist. Among silane compounds, water-soluble 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl))-3-aminopropyltrimethoxysilane, N-2- (aminoethyl) )) - 3-aminopropyltriethoxysilane, N-2- (aminoethyl)) - 3-aminopropyl methyl dimethoxy silane is preferred. The density | concentration of a silane compound is 0.1-5 mass%, Preferably it is 0.3-4 mass%, More preferably, it is 0.5-3 mass%. If the concentration is less than 0.1% by mass, sufficient adhesion strength between the copper surface and the resin cannot be obtained, and if the concentration exceeds 5% by mass, a further adhesion strength cannot be obtained, which is economically undesirable. The silane compound is fixed by dipping at 20 to 40 ° C. for 30 to 120 seconds and then drying at 100 to 150 ° C. for 30 to 120 minutes.

  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 / min under the processing conditions of 30 ° C. Preferably, it is 0.4-2 μm / min. Particularly preferred is 0.5 to 1.5 μm / min.

  The peel strength is preferably 0.8 kgf / cm or 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 treatment liquid 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.

  For the treatment method according to the metal surface treatment solution of the present invention is not particularly limited soaking, means spraying or the like is appropriately selected. The processing time is appropriately determined depending on the thickness of the copper or copper alloy to be dissolved.

  In addition, the metal surface treatment liquid 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 an electron microscope S-4700 manufactured by Hitachi, Ltd.
-Copper etching amount measuring method: It calculated by the mass method by the following formula | equation.
Etching amount = (mass before treatment−mass after treatment) / (treatment area × 8.92)

Example 1
After electrolytic copper foil (Mitsui Metals Mining 3EC-III) was etched by 1 μm with an etchant (Mitsubishi Gas Chemical CPE-700) to clean the copper foil surface, the first treatment liquid shown in Table 1 Etching 0.3 μm by immersion at 30 ° C. using the two treatment liquids, followed by washing with water and drying. 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, an interlayer insulating material (GX-13: manufactured by Ajinomoto Fine-Techno Co., Ltd.) was laminated on the electrolytic copper foil described above and heated and pressed. 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.

Example 2
The same procedure as in Example 1 was performed except that the third treatment liquid was added from Example 1. The Ra value was 0.25 μm, and the peel strength was 1.20 kgf / cm.

Example 3
The same procedure as in Example 1 was performed except that the kind of inorganic acid, the kind of halogen, the kind of azole, and the kind of silane compound were changed from Example 2. The Ra value was 0.25 μm, and the peel strength was 1.20 kgf / cm.

Comparative Example 1
In the composition of only the first treatment liquid, another embodiment 1 results carried out in the same manner as, Ra value is 0.25 [mu] m, the peel strength was 0.70kgf / cm.

Comparative Example 2
The second treatment solution was the same as in Example 1 except that the inorganic acid was not added. The Ra value was 0.25 μm, and the peel strength was 0.70 kgf / cm.

Comparative Example 3
The other treatment was performed in the same manner as in Example 1 except that the composition was not added with hydrogen peroxide. The Ra value was 0.25 μm, and the peel strength was 0.70 kgf / cm.

Comparative Example 4
The other processes were performed in the same manner as in Example 1 except for the composition of the first treatment liquid and the third treatment liquid (without the second treatment liquid). The Ra value was 0.25 μm, and the peel strength was 0.70 kgf / cm.

Comparative Example 5
The composition was the same as that described in Example 3 of Patent Document 1, and the others were performed in the same manner as in Example 1.
The Ra value was 0.60 μm, and the peel strength was 0.45 kgf / cm.

Comparative Example 6
The same etching solution as in Example 1 of Patent Document 3 was used, and the others were performed in the same manner as in Example 1. As a result, the Ra value was 0.60 μm and the peel strength was 0.45 kgf / cm.

Comparative Example 7
Using the same etchant as that in Example 1 of Patent Document 5, another embodiment 1 results carried out in the same manner as, Ra value is at 0.60 .mu.m, peel strength was 0.45kgf / cm.

Comparative Example 8
The same etching solution as in Example 1 of Patent Document 6 was used, and the others were performed 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 9
Using the same etchant as that in Example 1 of Patent Document 7, another embodiment 1 results carried out in the same manner as, Ra value is at 0.65 .mu.m, peel strength was 0.45kgf / cm.

  From the above results, the laminate treated with the surface treatment liquid of the present invention has a surface roughness (Ra value) of 0.30 μm or less, but has a high peel strength (peel strength) and is in close contact with the interlayer insulating material. It can be seen that the properties are good.

Claims (13)

  A method 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, comprising hydrogen peroxide 0.1 to 1% by mass, inorganic acid 0.3 to 2% by mass, halogen ion 0 After treatment with a first treatment liquid containing 0.0001 to 0.0003 mass% and triazoles 0.01 to 0.2 mass%, hydrogen peroxide 1 to 30 mass%, inorganic acid 0.001 to 0 metal surface treatment method, which comprises treating the metal wire surface using a second treatment solution containing .1% by weight.   Furthermore, the metal surface treatment method characterized by processing the surface of this metal wiring using the 3rd process liquid characterized by containing 0.1-5 mass% of silane compounds.   The metal surface treatment method according to claim 1 or 2, wherein the inorganic acid is at least one inorganic acid selected from nitric acid, sulfuric acid, and phosphoric acid.   The metal surface treatment method according to claim 1 or 2, wherein the halogen ions are chlorine ions or bromine ions.   The metal surface according to claim 1 or 2, wherein the triazole is at least one triazole selected from 1H-benzotriazole, 4-methylbenzotriazole and 5-methylbenzotriazole. Processing method.   The metal surface treatment method according to claim 1 or 2, wherein a mass ratio of the halogen ion to the triazole (halogen ion / triazole) is 0.0002 to 0.003.   The silane compound is 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl))-3-aminopropyltrimethoxysilane, N-2- (aminoethyl))-3- 3. The metal surface treatment method according to claim 2, wherein the metal surface treatment method is at least one selected from aminopropyltriethoxysilane and N-2- (aminoethyl))-3-aminopropylmethyldimethoxysilane.   First treatment containing 0.1 to 1% by weight of hydrogen peroxide, 0.3 to 2% 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 Treatment with a second treatment liquid containing 1 to 30% by weight of hydrogen peroxide and 0.001 to 0.1% by weight of an inorganic acid, and 0.1 to 5% by weight of a silane compound. Using the third treatment liquid characterized in that 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 0.5 μm or less. Production method.   The method for manufacturing a wiring board according to claim 8, wherein the inorganic acid is at least one selected from nitric acid, sulfuric acid, and phosphoric acid.   9. The method for manufacturing a wiring board according to claim 8, wherein the halogen ion is at least one selected from chlorine ion or bromine ion.   The method for producing a wiring board according to claim 8, wherein the triazole is at least one selected from 1H-benzotriazole, 4-methylbenzotriazole, and 5-methylbenzotriazole.   9. The method for manufacturing a wiring board according to claim 8, wherein the mass ratio of the concentration of halogen ions to triazoles (halogen ions / triazoles) is 0.0002 to 0.003.   The silane compound is 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl))-3-aminopropyltrimethoxysilane, N-2- (aminoethyl))-3- 9. The method of manufacturing a wiring board according to claim 8, wherein the wiring board is at least one selected from aminopropyltriethoxysilane and N-2- (aminoethyl))-3-aminopropylmethyldimethoxysilane.