KR20190133709A - Electroplating solution for iron-nickel alloy peeling, opening method using the same, method for manufacturing circuit board - Google Patents

Abstract

The iron-nickel alloy was electroplated by an iron-nickel alloy peeling electroplating solution, an opening method using the same, and a method of manufacturing a circuit board, wherein the iron-nickel alloy electroplating solution contained acetylene alcohol again. It provides a technique that can be used for circuit formation itself by plating.

Description

Electroplating solution for iron-nickel alloy peeling, opening method using the same, method for manufacturing circuit board

The present invention relates to an electroplating solution for iron-nickel alloy filling, a method of filling openings using the same, and a method of manufacturing a circuit board.

In the case of an iron-nickel alloy, especially a composition called an invar composition, it is generally used in photomasks, bimetals, and the like because the thermal expansion coefficient is low and the dimensions do not change with temperature.

Until now, since iron-nickel alloys were solvent alloys, they could not be used for circuit formation itself, but in recent years, techniques for depositing iron-nickel alloys by electroplating have been reported (Patent Document 1). Was expected to use.

But. When attempting to perform via peeling etc. with an iron-nickel alloy using the technique of patent document 1, since there was a problem of conformal precipitation, there existed a problem that peeling could not be performed sufficiently.

1. Japanese Patent No. 6084899

Accordingly, the present invention provides a technique in which the iron-nickel alloy can be used for circuit formation itself by electroplating.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to solve the said subject, the inventors unexpectedly found the acetylene alcohol which is an active ingredient of the conventionally well-known etching agent for iron-nickel alloys (for example, Unexamined-Japanese-Patent No. 2001-11661). By adding in nickel alloy electroplating liquid, it discovered that the circuit formation, such as peeling of opening parts, such as a via, can be performed and completed this invention.

That is, the present invention is an electroplating solution for iron-nickel alloy peeling, wherein the iron-nickel alloy electroplating solution contains acetylene alcohol again.

The present invention is also a method of filling an opening, wherein the substrate having the opening is electroplated with the electroplating solution for iron-nickel alloy filling.

Furthermore, the present invention is a method of manufacturing a circuit board, wherein the substrate having an opening is electroplated with the electroplating solution for iron-nickel alloy filling.

Furthermore, the present invention is a circuit board characterized in that the opening is filled with an iron-nickel alloy.

The electroplating solution for iron-nickel alloy filling of the present invention can be filled into a substrate having an opening such as a via. In addition, the iron-nickel alloy peeled as described above has a small variation in composition from the opening to the depth direction. Moreover, the iron-nickel alloy filled as described above does not require heat treatment.

Therefore, the electroplating solution for iron-nickel alloy filling of the present invention is very suitable for circuit formation such as filling of openings such as vias.

1 is a cross-sectional photograph of a substrate obtained in Example 2. FIG.
FIG. 2 shows measurement points of EDS of the substrate obtained under condition 2 of 2. FIG.
3 is a cross-sectional photograph of a substrate obtained in Example 4. FIG.

The electroplating solution for iron-nickel alloy filling of the present invention (hereinafter referred to as the "plating solution of the present invention") contains acetylene alcohol again in the iron-nickel alloy electroplating solution.

The acetylene alcohol used in the plating solution of the present invention is not particularly limited as long as it has a triple bond and an OH group between the carbons in the structure, and examples thereof include propargyl alcohol, butynediol, pentindiol, hexyndiol, and octindiol. . In addition, these acetylene alcohols may have substituents, such as an alkyl group and a hydroxy ethyl group. Among these acetylene alcohols, in order to reduce the variation in the composition of the iron-nickel alloy when peeled, acetylene alcohol having 5 or more carbon atoms is preferable, and especially hexyndiol is preferable. These acetylene alcohols may be used alone or in combination of two or more.

Although content of the acetylene alcohol in the plating liquid of this invention is not specifically limited, For example, it is 0.001-1 mass% (henceforth only "%"), Preferably it is 0.005-0.5%.

The iron-nickel alloy electroplating solution as the base of the plating solution of the present invention is not particularly limited. For example, metal ions such as iron ions and nickel ions, complexing agents such as gluconic acid, malic acid, tartaric acid, boric acid, acetic acid, and the like. The thing containing a buffer is mentioned. More specific examples of the electroplating solution for iron-nickel alloys include chloride baths, sulfate baths, sulfate-chloride baths, cyan baths, tartaric acid baths, pyrophosphate baths, watt baths, and sulfamic acid baths. Among these, a watt bath and a sulfamic acid bath are preferable.

More preferred as the iron-nickel alloy electroplating solution serving as the base of the plating solution of the present invention is the following general formula (1)

The unsaturated sulfonic acid compound represented by this is contained.

In the unsaturated sulfonic acid compound, R is a vinyl group or an ethynyl group, preferably a vinyl group. Moreover, X may be substituted, It is an alkylene group or a phenylene group, Preferably it is an unsubstituted alkylene group or a phenylene group, More preferably, it is an unsubstituted alkylene group. Examples of the substituent include an alkyl group having 1 to 3 carbon atoms, a halogen and a hydroxyl group. Examples of the alkylene group include one having 1 to 10 carbon atoms, preferably one having 1 to 3 carbon atoms, and more preferably one having 1 to 3 carbon atoms. . Moreover, Y is an alkali metal, preferably lithium, sodium, potassium, and more preferably sodium.

More specific examples of the unsaturated sulfonic acid compound include sodium aryl sulfonate, sodium vinyl sulfonate, sodium propene sulfonate, and the like, and sodium aryl sulfonate is preferable. These unsaturated sulfonic acid compounds may be used alone or in combination of two or more thereof.

The content of the unsaturated sulfonic acid compound in the plating solution of the present invention is 1 to 10%, preferably 4 to 8%.

Particularly preferred as the iron-nickel alloy electroplating solution serving as the base of the plating solution of the present invention is 4-12 g / L of unsaturated sulfonic acid compound and iron represented by the general formula (1), preferably 6-10 g / L, nickel 20 to 50 g / L, preferably 25 to 40 g / L. In the case of such an iron-nickel alloy electroplating solution, the composition of the iron-nickel alloy in the case of filling in the opening portion is 100% of the total amount, and 55 to 64% of iron and 36 to 45% of nickel.

The plating solution of the present invention may further contain cobalt, molybdenum and tungsten. The addition amount of cobalt, molybdenum, and tungsten in this case is not specifically limited, For example, it is 1-100 g / L, Preferably it is 1-50 g / L. Examples of cobalt, molybdenum, and tungsten sources include cobalt sulfate, cobalt sulfamate, sodium molybdate and sodium tungstate.

To the plating solution of the present invention, a stress relaxation agent such as sodium saccharate added to a conventionally known iron-nickel alloy electroplating solution may be added.

Below, the composition of a watt bath and a sulfamic acid bath is described as a preferable aspect of the iron- nickel-alloy electroplating liquid used as the base of this invention plating solution.

<Watt bath>

Nickel sulfate: 50 to 125 g / L, preferably 60 to 100 g / L

Nickel chloride: 40 to 80 g / L, preferably 50 to 70 g / L

Boric acid: 30-60 g / L

Ferrous sulfate: 20 to 60 g / L, preferably 35 to 50 g / L

Sodium gluconate: 20-80 g / L, preferably 50-60 g / L

Saccharin sodium: 1-5 g / L, preferably 2-4 g / L

Sodium arylsulfonic acid: 1.5-10 g / L, preferably 3.5-8.5 g / L

<Sulfamic acid bath>

Nickel sulfamate: 90-250 g / L, preferably 140-190 g / L

Boric acid: 30-60 g / L

Nickel bromide: 5-15 g / L, preferably 6-10 g / L

Iron sulfamate: 25-75 g / L, preferably 40-60 g / L

Sodium gluconate: 20-80 g / L, preferably 50-60 g / L

Saccharin sodium: 1-5 g / L, preferably 2-4 g / L

Sodium arylsulfonic acid: 1.5-10 g / L, preferably 3.5-8.5 g / L

The plating liquid of the present invention can be filled with an opening by electroplating a substrate having an opening. The method of electroplating is not specifically limited, For example, the method of immersing this in the plating liquid of this invention after performing pretreatment, such as alkali degreasing and acid activity, to the board | substrate which has an opening part is mentioned.

The board | substrate which can be electroplated with the plating liquid of this invention is not specifically limited, For example, what was formed from resin, ceramics, glass, etc. which added electroconductive process, such as electroless plating, PVD, CVD process previously, etc. are mentioned. . In this invention, an opening means things, such as a via. The size of the opening is not particularly limited. For example, the diameter of the opening is about 5 to 150 µm, the depth is about 10 to 100 µm, and the aspect ratio is about 0.1 to 2, if it is a via.

The conditions of the electroplating are not particularly limited, and if the conditions for filling by ordinary electroplating are used, for example, iron and nickel are used in combination with the anode at a bath temperature of 30 to 60 ° C, and the cathode current density is used. It is good to carry out at 0.05-3A / dm <^2> until the opening part is filled. In addition, during electroplating, it is preferable to stir with a paddle or the like.

When the electroplating is performed on the substrate having the opening using the plating solution of the present invention as described above, the opening of the substrate can be filled. In the case of the present invention, the filled iron-nickel alloy also does not require heat treatment.

Moreover, when an opening part is filled using the plating liquid of this invention, there is little variation in the composition from the opening part of the iron-nickel alloy filled in the opening part to the depth direction.

Furthermore, in the plating solution of the present invention, when the openings are filled with a acetylene alcohol having a carbon number of 5 or more, in particular, a plating solution using hexyndiol, there is little variation in the composition from the openings to the depth direction. The difference between the composition from the bottom up to a film thickness of 30% and the surface composition of the opening is ± 10% or less. In addition, the composition from the opening of the filled iron-nickel alloy to the depth direction can be measured by energy dispersive X-ray analysis (EDS) or the like.

As described above, the opening of the substrate having the opening is filled with the iron-nickel alloy using the plating solution of the present invention, and then the chemical mechanical polishing or lamination process, the peeling plating, the filling of the conductive paste and the bump formation are performed again. Circuit boards filled with iron-nickel alloys can be produced.

Moreover, among the said circuit boards, the multilayer via wiring board which can form a stack via at the time of lamination | stacking on the upper part of the opening part after filling, and can form the pad for mounting an electronic component is preferable.

Since the circuit board manufactured in this way uses the low thermal expansion alloy as a wiring, it is possible to suppress deterioration such as cracks caused by the difference in thermal expansion coefficient between the metal and the resin.

EXAMPLE

Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these Examples at all.

Example # 1

Preparation of electroplating solution for iron-nickel alloys:

Nickel sulfamate tetrahydrate 156 g / L, boric acid 30 g / L nickel bromide 7 g / L, iron sulfamate pentahydrate 47 g / L, sodium gluconate 60 g / L, sodium saccharin 3.2 g / L and arylsulfonic acid 16 ml / L of sodium (36%) and 1.0 g of hexyndiol were added and mixed to prepare an electroplating solution for iron-nickel alloys. The pH of this plating bath was 3.8, and the contents of nickel and iron were 30 g / L and 7.5 g / L, respectively.

Comparative Example 1

Preparation of electroplating solution for iron-nickel alloys:

An electroplating solution for iron-nickel alloy was prepared in the same manner as in Example 1 except that the compound did not contain hexyndiol.

Example # 2

Filling substrates with vias:

Using the electroplating solution for iron-nickel alloys prepared in Example 1 and Comparative Example 1, peeling of the substrate having a via under the conditions described in Table 1 below was performed. The cross-sectional photograph after peeling is shown in FIG. Moreover, the measurement point of EDS of the board | substrate after electroplating on condition 2 was shown in FIG. 2, and the composition of iron and nickel in the measurement point is shown in Table 2. FIG.

<Substrate>

The openings were blind vias, and electroless copper plating was used for circuit boards having a diameter of the blind vias of 70 m, a depth of 40 m, and an aspect ratio of 0.57.

Plating amount Current density Plating time Liquid temperature Condition 1 Example 1 1 A / dm ² 60 minutes 60 ℃ Condition 2 Example 1 1 A / dm ² 120 minutes 60 ℃ Condition 3 Example 1 1.5dm ² 120 minutes 60 ℃ Condition 4 Comparative Example 1 1 A / dm ² 60 minutes 60 ℃

Measuring point Furtherance(%) iron nickel  ① Surface 63 37  ② 30㎛ thickness from bottom of beer 63 37  ③ 20㎛ thickness from bottom of beer 59 41  ④ 10㎛ thickness from bottom of beer 57 43

The iron-nickel alloy electroplating solution of the present invention containing hexyndiol could fill vias, but the iron-nickel alloy electroplating solution containing no hexyndiol could not fill vias. It was also found that the iron-nickel alloy peeled by the present invention has a small variation in composition from the opening to the depth direction.

Example # 3

Preparation of electroplating solution for iron-nickel alloys:

An electroplating solution for iron-nickel alloys was prepared in the same manner as in Example 1 except that hexyndiol was 0.02 g of propargyl alcohol.

Example # 4

Filling substrates with vias:

Except using the electroplating solution for iron-nickel alloys of Example 3, it peeled to the board | substrate similar to Example 2 on the conditions similar to the condition 1 of Example 2. The cross-sectional photograph after peeling is shown in FIG. Moreover, the composition of iron and nickel measured by EDS similarly to Example 2 is shown in Table 3.

Measuring point Furtherance(%) iron nickel  ① Surface 66 34  ② 30㎛ thickness from bottom of beer 66 34  ③ 20㎛ thickness from bottom of beer 58 42  ④ 10㎛ thickness from bottom of beer 52 47

The iron-nickel alloy electroplating solution of the present invention containing propargyl alcohol was able to peel vias. In addition, it was found that the iron-nickel alloy peeled by the present invention had a smaller variation in composition from the opening to the depth direction when hexyndiol was used than when propargyl alcohol was used.

Example # 5

Preparation of electroplating solution for iron-nickel alloys:

An electroplating solution for iron-nickel alloys was prepared in the same manner as in Example 1 except that hexyn diol was 1.5 g / L of dimethyloctyne diol.

Example # 6

Preparation of electroplating solution for iron-nickel alloys:

Nickel sulfate 75g / L in water, boric acid 30g / L, nickel chloride 55g / L, ferrous sulfate 37.5g / L, sodium gluconate 60g / L, sodium saccharine 3.2g / L and sodium arylsulfonic acid (36%) 16ml / L and 1.0 g of hexyndiol were added and mixed to prepare an electroplating solution for iron-nickel alloys. The pH of this plating bath was 3.0 and the contents of nickel and iron were 30 g / L and 7.5 g / L, respectively.

Example # 7

Preparation of Electroplating Solution for Iron-Nickel-Cobalt Alloy:

Nickel sulfamate tetrahydrate 126g / L, boric acid 30g / L, nickel bromide 7g / L, iron sulfamate pentahydrate 50g / L, sulfamate cobalt tetrahydrate 3.5g / L, sodium gluconate 60g / L , 3.2 g / L sodium saccharin, 16 ml / L sodium aryl sulfonate (36%), and 1.0 g of hexyndiol were added and mixed to prepare an electroplating solution for iron-nickel alloys. PH of this plating bath was 3.8, and content of ni (DELTA), iron, and cobalt was 30 g / L, 7.5 g / L, and 0.625 g / L, respectively.

[Industry availability]

The electroplating solution for iron-nickel alloy peeling of this invention can be used for circuit formation, such as peeling of opening parts, such as a via.

Claims (9)

An electroplating solution for iron-nickel alloy filling, wherein the iron-nickel alloy electroplating solution contains acetylene alcohol again. The electroplating solution according to claim 1, wherein the acetylene alcohol has 5 or more carbon atoms. The electroplating solution for iron-nickel alloy peeling according to claim 1, wherein the acetylene alcohol is hexyndiol. The iron-nickel alloy electroplating solution according to any one of claims 1 to 3, wherein 4 to 12 g / L of iron, 20 to 50 g / L of nickel, and the following general formula (1)

(Wherein R is a vinyl group or an ethynyl group, X is an alkylene group or a phenylene group which may be substituted, and Y represents an alkali metal.)
An electroplating solution for iron-nickel alloy filling, containing an unsaturated sulfonic acid compound represented by. A method of peeling an opening, wherein the substrate having the opening is electroplated with an electroplating solution for iron-nickel alloy filling according to any one of claims 1 to 4. A substrate having an opening is electroplated with an electroplating solution for iron-nickel alloy filling according to any one of claims 1 to 4. A circuit board characterized in that the opening is filled with an iron-nickel alloy. The circuit board according to claim 7, wherein the iron-nickel alloy has 55 to 64 mass% of iron and 36 to 45 mass% of nickel. The circuit board of Claim 7 or 8 which is a multilayer printed wiring board.

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