KR101826062B1 - Electroless tin high speed plating solution - Google Patents

Abstract

The present invention relates to an electroless tin high speed plating solution treated in an electronic component. According to the present invention, provided is an electroless tin plating solution, which can obtain a plating thickness when plating electroless tin in a short time, and further, can effectively restrict corrosion of a lower metal layer leading to a defect of a void or overplating shape.

Description

[0001] ELECTROLESS TIN HIGH SPEED PLATING SOLUTION [0002]

More particularly, the present invention relates to an electroless tin plating solution for electronic parts, and more particularly, to an electroless tin plating solution for electroplating tin plating for electronic parts, which is capable of obtaining thickness plating in a short time during electroless tin plating, The present invention relates to an electroless tin plating solution capable of efficiently suppressing an electroless tin plating solution.

Electroless plating is one of the widely used technologies for various applications such as circuit formation, interconnection, and surface treatment in the fields of electronic parts, substrates, capacitors, and semiconductors. Recently, the high density / The characteristics of the plating layer formed by such electroless plating become more important by the high integration.

Fig. 1 shows a corrosion pattern of a lower metal layer in electroless tin plating mainly used for automobile parts, substrates, capacitors, electronic parts and the like. In the electroless tin plating, most of the plating proceeds due to the substitution reaction, in which plating is progressed by receiving the electrons generated by oxidation of one metal by the different reduction potential difference between the two metals instead of the other metal ions. When a substitution reaction or partial over-substitution reaction occurs, voids or overplating type defects occur between the interfaces as shown in the photograph. Thus, a dense coating film which does not cause defects of void or overflowing type as described above was made, but the thickness plating was difficult in a short time.

Precedent literature information: Patent disclosure KR1020050092132A

The present invention provides an electroless tin plating solution capable of efficiently achieving thickness plating during electroless tin plating in a short time, as well as effectively suppressing corrosion of a lower metal layer that has caused defects such as voids or overflows.

According to one aspect of the present invention, there is provided an electroless tin plating solution for high-speed plating comprising a compound represented by the following formula (1), a compound represented by the following formula (2) and a compound represented by the following formula (3)

Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² independently of one another are hydrogen, An alkyl group having 1 to 20 carbon atoms, a primary amine group (NH ₂ ) or a carboxyl group (COOH), wherein R ¹ and R ² ; R ³ , R ⁴ , R ⁵ and R ⁶ ; R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² each have two or more functional groups selected from a primary amine group (NH ₂ ) and a carboxyl group (COOH).

In the present invention, R ¹ and R ² may each be a primary amine group (NH ₂ ).

In the present invention, R ³ , R ⁴ , R ⁵ and R ⁶ may each be hydrogen, a hydroxyl group (OH), an alkyl group having 1 to 20 carbon atoms, a primary amine group (NH ₂ ) or a carboxyl group (COOH).

In the present invention, R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² may have two kinds of carboxyl groups (COOH), two kinds of hydroxyl groups (OH), and two kinds of hydrogen.

In the present invention, the plating solution contains the compound represented by Formula 1, the compound represented by Formula 2 and the compound represented by Formula 3 in the range of more than 125 g / L to 500 g / L, , And the content ratio between the compound represented by the formula (2) and the compound represented by the formula (3) is 1: 0.5 or more: 0.5 or more (formula 1: formula 2: w / v in formula 3).

Further, in the present invention, the plating solution may contain more than 20 g / L of antioxidant To 500 g / L or less, wherein the antioxidant is selected from the group consisting of catechol, resorcinol, phloroglucinol, pyrogallol, dihydroxynaphthalene, cresol, hydrazine, And salts thereof.

In the present invention, the plating solution may contain a surfactant in a range of 0.01 g / L to 100 g / L, wherein the surfactant is selected from the group consisting of alkane, polyalkylene glycol phenyl ether, phenol, naphthol, bisphenol, arylalkylphenol, sorbitan Esters and aliphatic amides.

The polyethylene glycol phenyl ether may be a compound represented by the following formula (4).

Wherein R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ are independently hydrogen, a hydroxyl group (OH) or an alkyl group having 1 to 20 carbon atoms, and n is 6 to 10.

Wherein ^{R 13, R 14, R 15} , R 16 and R ¹⁷ is an alkyl group having 1 to 20, R ¹⁸ may be hydrogen.

In the present invention, the plating solution contains an organic sulfonic acid in a range of more than 150 g / L to less than 300 g / L, wherein the organic sulfonic acid is methanesulfonic acid, ethanesulfonic acid, 1-propanesulfonic acid, 2-propanesulfonic acid, And salts thereof. ≪ / RTI >

Also, in the present invention, the plating solution comprises a first tin salt as a divalent tin source in an amount of 1 g / L to 50 g / L, wherein the first tin salt is selected from the group consisting of tin chloride, tin sulfate, tin pyrophosphate, tin citrate, Tin, tin methanesulfonate, tin 1-propanesulfonate, tin pyrophosphate, tin methanesulfonate, and methane tartaric acid.

In the present invention, the thickness of the tin coating film measured at 20 minutes after electroless plating at 60 to 90 DEG C is 2.07 to 2.77 mu m, the thickness of the tin coating film measured at 60 minutes is 2.7 to 4.0 mu m, Wherein the tin coating has a thickness of 7 to 9 占 퐉, wherein the tin coatings are formed without overplating or voids.

According to the present invention, it is possible not only to achieve thickness plating in a short time during electroless plating, but also to effectively suppress corrosion of a lower metal layer which has caused defects such as voids or overplating.

FIG. 1 is a photograph showing corrosion of a lower copper layer as a result of electroless tin plating according to the prior art, resulting in occurrence of void (corresponding to a) and overflow (corresponding to b).
FIG. 2 is a photograph showing the plating thickness measured for 1 hour (corresponding to a) and 3 hours (corresponding to b) when high-speed plating is performed using the electroless plating solution according to an embodiment of the present invention.
FIG. 3 is a photograph showing voids and overflow phenomenon observed at 20 minutes and 60 minutes when high-speed plating is performed using the electroless plating solution according to an embodiment of the present invention. FIG. 3 (a) and (b) (C) and (d) show overflow phenomenon when performing plating for 20 minutes at 68 ° C. In this case, when the plating was performed at a working temperature of 68 ° C for 20 minutes, It can be seen that it was not observed.
Figs. 4 to 7 are photographs showing the appearance when the components of the high-speed plating solution have an improper content range, Fig. 4 is a plating solution of Comparative Example 2, Fig. 5 is a plating solution of Comparative Example 3, Fig. 6 is a plating solution of Comparative Example 4 And Fig. 7 corresponds to the case of using the plating solution of Comparative Example 5, respectively.
FIG. 8 is a photograph showing the appearance when the speed is excessively increased by the low-speed plating solution. As the low-speed plating solution, the plating solution of Comparative Example 6 was used.

Hereinafter, preferred embodiments of the electroless plating solution according to the present invention will be described in detail. For reference, the present invention is not limited to the specific embodiments.

In the present invention, in order to effectively suppress the corrosion of the lower metal layer which can not only achieve thickness plating during electroless plating in a short period of time but also cause defects in the form of voids or overflowing, a compound represented by the following Chemical Formula 1, And a compound represented by the following general formula (3).

[Chemical Formula 1]

(2)

(3)

Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² independently of one another are hydrogen, An alkyl group having 1 to 20 carbon atoms, a primary amine group (NH ₂ ) or a carboxyl group (COOH), wherein R ¹ and R ² ; R ³ , R ⁴ , R ⁵ and R ⁶ ; R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² each have two or more functional groups selected from a primary amine group (NH ₂ ) and a carboxyl group (COOH).

For example, when R ¹ and R ² are each a primary amine group (NH ₂ ), the metal ion is oxidized as a component that substitutes tin on a copper or copper alloy that is theoretically impossible when a tin or tin alloy is plated on a copper substrate And the like. For reference, when the concentration is low, the liquid is unstable and the plating rate is slowed and the overflow easily occurs. In addition, the appearance of the plated sample may be uneven and voids may be caused. If the concentration is excessive May form a rough surface and the plating liquid may become unstable, so that it is necessary to select a proper concentration.

For example, R ³ , R ⁴ , R ⁵ and R ⁶ are hydrogen, a hydroxyl group (OH), an alkyl group having 1 to 20 carbon atoms, a primary amine group (NH ₂ ), and a carboxyl group (COOH) . In addition, it has an antioxidant effect, which suppresses oxide formation on the surface of the plating and can easily inhibit the oxidation of gray, that is, the surface of the tin or tin alloy. For reference, if the content is too small, the activity tends to become insufficient, and if the content is excessive, the bath stability may deteriorate and the manufacturing cost may increase.

As specific examples, R ³ is hydrogen, R ⁴ is an alkyl group having 1 to 20 carbon atoms, R ⁵ is a carboxyl group (COOH), and R ⁶ is a primary amine group (NH ₂ ).

For example, R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are used as auxiliary chelating agents having two kinds of carboxyl groups (COOH), two kinds of hydroxyl groups (OH) . If the content is too low, the color of the plating film becomes dark and causes pinholes on the surface of the plating. On the other hand, if the content is excessive, the increase in the plating speed can not be observed, And there is a possibility that it is easily precipitated.

As specific examples, each of R ⁷ and R ¹⁰ may be a carboxyl group (COOH), R ⁸ and R ¹¹ may be hydrogen, and R ⁹ and R ¹² may be a hydroxyl group (OH).

The plating solution according to the present invention may contain more than 125 g / L to 500 g / L, or more than 125 g / L to 200 g, for example, the compound represented by Formula 1, the compound represented by Formula 2 and the compound represented by Formula 3, / L, and the content ratio between the compound represented by the formula (1) and the compound represented by the formula (2) and the compound represented by the formula (3) within this range is 1: 0.5 or more: 0.5 or more (formula 2: w / v in the formula (3)) is preferable because the plating rate can be increased and the plating layer can be uniformly formed, pinholes are not formed in the outer appearance, and the formation structure of the tin layer can be improved.

For example, the content ratio between the compound represented by Formula 1 and the compound represented by Formula 2 and the compound represented by Formula 3 is 1: 0.5 to 1: 0.5 to 1 (Formula 1: Formula 3: Of w / v).

The compound represented by Formula 1 may be, for example, more than 50 g / L to less than 500 g / L, 80 to 100 g / L, or 95 to 105 g / L. If it is less than 50 g / L, the plating layer may be uneven and the life of the plating solution may be shortened. If it exceeds 500 g / L, microvoids may be caused in the plating layer.

The compound represented by Formula 2 may be, for example, 10 to 100 g / L, 20 to 80 g / L, or 35 to 75 g / L, and a uniform coating film having a uniform outer appearance and a uniform thickness deviation Can be provided.

The compound represented by the general formula (3) may be, for example, more than 25 g / L to less than 100 g / L, 30 to 80 g / L, or 35 to 75 g / And the speed is maintained constantly. However, when the amount is excessive, the speed is inhibited and the plating liquid may be precipitated.

The plating solution according to the present invention may further contain, if necessary, ethylenediamine tetraacetic acid (EDTA) to the compound represented by the above general formulas 1, 2 and 3 so as to reinforce the phenomenon that metal ions are prevented from being precipitated during the plating, ), At least one of citric acid, sodium citrate, gluconic acid, lactic acid, glycolic acid, malonic acid, glucoheptonic acid, formic acid, acetic acid, propionic acid and diglycolic acid.

The plating solution according to the present invention may be prepared by dissolving the compound represented by Chemical Formula 3 in a solvent such as ethylenediamine tetraacetic acid (EDTA), sodium citrate (EDTA) or the like in consideration of the phenomenon that metal ions are prevented from being precipitated during oxidation, Sodium citrate, gluconic acid, lactic acid, glycolic acid, malonic acid, glucoheptonic acid, formic acid, acetic acid, propionic acid and diglycolic acid.

The plating solution according to the present invention may contain an antioxidant in an amount of more than 20 g / L to 500 g / L or less, or 20 g / L to 300 g / L or less, or 100 g / L to 150 g / And can induce rapid movement of hydrogen bubbles within this range to provide denseness, uniformity and thick film formation of the plated film in a short time.

For reference, if the content of the antioxidant is too small, the effect of preventing the tetravalent divalent tin source from being oxidized is small and the lifetime of the plating solution is shortened. If the content is too much, the stability of the working solution is deteriorated and the smoothness and uniformity And the resulting porous tin deposits may also be formed.

The antioxidant may be, for example, a hydroxyaryl compound in which at least one hydroxy radical is bonded to an aromatic nucleus carbon atom, hydrazine, and hypophosphorous acid. Examples of the hydroxyaryl compound having at least one hydroxy radical bonded to the aromatic nucleus carbon atom include catechol, resorcinol, phloroglucinol, pyrogallol, dihydroxynaphthalene, Cresol and the like.

The plating solution according to the present invention may contain a surfactant in an amount of 0.01 to 100 g / L or 1 g / L to 10 g / L or less, for example. Too small a surfactant will cause a thickness variation of the plating, and if it is too much, the presence of excessive bubbles may cause surface staining.

The surfactant contributes to the improvement of appearance, denseness, smoothness, adhesion and the like of the plated film. Examples of the surfactant include alkane, polyalkylene glycol phenyl ether, phenol, naphthol, bisphenol, arylalkylphenol, sorbitan ester and aliphatic Amides, and the like.

The polyethylene glycol phenyl ether may be, for example, a compound represented by the following general formula (4).

[Chemical Formula 4]

Wherein R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ are independently hydrogen, a hydroxyl group (OH) or an alkyl group having 1 to 20 carbon atoms, and n is 6 to 10.

For example, R ¹³ , R ¹⁴ , R ¹⁵ , R ^16, and R ¹⁷ may be an alkyl group having 1 to 20 carbon atoms, and R ¹⁸ may be hydrogen.

As specific examples, R ¹³ , R ¹⁴ , R ¹⁵ , R ^16, and R ¹⁷ may be a methyl group or an ethyl group, and R ¹⁸ may be hydrogen. In this case, pinholes in the tin plating film or bubble dropping in the plating solution can be facilitated .

A solvent such as ethylene glycol, glycerin or polyethylene glycol may be added for the purpose of facilitating the removal of the pinholes or the bubbling of the plating solution described above. In this case, the formation of tin oxide and the formation structure of the tin layer Can be improved.

The plating solution according to the present invention may contain an organic sulfonic acid in an amount of more than 150 g / L to less than 300 g / L, or more than 150 g / L to 250 g / L, for example. When it is used at 150 g / L or less, the plating rate is accelerated but the roughness of the surface is increased and the overflowing is undesirably undesirable. When the content is more than 300 g / L, the plating thickness is unevenly formed or the thickness is thinned .

The organic sulfonic acid may be at least one selected from the group consisting of methanesulfonic acid, ethanesulfonic acid, 1-propanesulfonic acid, 2-propanesulfonic acid, 1 -butylsulfonic acid and salts thereof.

The plating solution according to the present invention may contain 1 g / L to 50 g / L, for example, 7 g / L to 15 g / L as a tin salt as a divalent tin source. . If the content is less than 7 g / L, the plating rate may be lowered and the plating layer may become uneven. If it exceeds 15 g / L, the cost becomes higher and the amount of tin in the plating solution becomes larger.

The first tin salt may be one selected from the group consisting of tin chloride, tin sulfate, tin pyrophosphate, tin citrate, tin oxalate, tin methanesulfonate, tin 1-propanesulfonate, tin pyrophosphate, tin methanoate sulfonate and methane tartaric acid. It can be more than a species.

The plating solution according to the present invention is a plating solution for high-speed plating, which provides smoothness, uniformity and thick film formation of a plating film. Specifically, the thickness of the tin coating film measured at 20 minutes under electroless plating at 60 to 90 ° C is 2.07 The thickness of the tin coating measured at 60 minutes may be 2.7 to 4.0 mu m, the thickness of the tin coating measured at 180 minutes may be 7 to 9 mu m, and the tin coatings may be overlapped is formed without overplating or voiding.

For reference, the reaction time of the high-speed plating is sufficient to form a tin coating having a thickness of 0.1 to 10 탆, or 0.1 to 6 탆, for 30 seconds to 3 hours, or 1 to 90 minutes.

The reaction temperature of the high-speed plating may be 60 to 90 ° C, 60 to 70 ° C or 65 to 70 ° C.

The plating solution according to the present invention may be subjected to a pretreatment process, if necessary. For example, a degreasing process, an etching process, and the like of the substrate may be performed.

The plating liquid according to the present invention proceeds on the contact-treated surface. The contact-treated surface is a contact-treated nucleus formed by a known method on a nonconductive substrate such as glass, a copper alloy such as copper alloy or tin Lt; / RTI > At this time, when a strong reducing agent such as sodium hypophosphite or borazane is added, tin plating is promoted. In the present invention, it is assumed that a reducing agent of at least 0.1 mol / L can be added to the solution for this purpose, and hydrogen is generated to activate the plating surface, thereby promoting plating.

Substrates include, but are not limited to, a modified semi additive process (MSAP) substrate, a semi additive process (SAP) substrate, an advanced modified semi additive process (AMSAP) substrate, a full additive process (FAP) Etc., and may be provided with a plating solution suitable for the copper or copper alloy layer,

The electronic component may be an MSAP substrate, an SAP substrate, an AMSAP substrate, an FAP substrate, or a PCB for an automobile electric field, according to the present invention.

Hereinafter, the structure and effects of the present invention will be described in detail through examples and comparative examples. However, it is to be understood that the present invention is not limited thereto.

<Examples>

Electroless tin plating solutions of Examples 1 and 2 and Comparative Examples 1 to 6 were prepared with the components and contents shown in Table 1 below.

division Tin salt
(Sn metal g / L) Methanesulfonic acid
(g / L) The compound of formula (1)
(R ¹ = R ² = NH ₂ ) The compound of formula 2
(R ³ = H, R ⁴ = C ₁ -C ₂₀ alkyl, R ⁵ = NH ₂ , R ⁶ = COOH) The compounds of formula ^{3 (R 7 = R 10 =} COOH, R 8 = R 11 = H, R 9 = R 12 = OH) Carp
(g / L) The compound of formula 4
^{(R 13 = R 14 = R} 15 = R 16 = R 17 = CH 3, R 18 = H, n = 9) Remarks Example 1 10 200 100 50 50 100 One Comparative Example 1 10 300 100 - 25 10 One Conventional low speed composition Comparative Example 2 10 350 50 - 100 10 One Comparative Example 3 10 150 100 - 25 10 One Comparative Example 4 10 150 100 50 25 10 One Comparative Example 5 10 200 100 50 50 20 One Comparative Example 6 10 150 100 50 10 150 10 Example 2 10 200 100 50 50 150 One

[Experimental Example]

&Lt; Pretreatment and Electroless Tin Plating Method >

Electroless tin plating was applied to a copper clad laminate (CCL) copper plate at 68 ° C with a dipping time of 1 hour / 3 hours using the electroless tin plating solution prepared in the components and contents of Example 1.

The CCL copper plate was used after the pretreatment process as follows. The CCL copper plate was degreased at 50 ° C for 3 to 4 minutes using a degreasing solution (SAC302, manufactured by the same company), and then washed with water. Subsequently, the substrate was etched at room temperature for 1 minute using an etching solution (manufactured by SE968M of its own product) and then washed with water.

The thickness of the 1 hour precipitation coating film measured using a scanning electron microscope (SEM) was 2.7 to 4.0 占 퐉, and the thickness of the 3 hour precipitation coating film was 7.0 to 9.0 占 퐉 (see Figs.

<Plating for overflowing and deposition rate measurement>

The MSAP substrate was subjected to the above electroless tin plating method and measured. Here, the MSAP substrate was used after being pre-treated as follows. One MSAP substrate was degreased at 50 ° C for 3 to 4 minutes using a degreasing liquid (SAC302, manufactured by the same company), and then washed with water. Subsequently, the substrate was etched at room temperature for 1 minute using an etching solution (manufactured by SE968M of its own product) and then washed with water.

Using an electroless tin plating solution prepared from the components and contents of Examples 1 to 2 and Comparative Examples 1 to 6 in Table 1, the dipping time at 68 ° C was 20 minutes / 60 minutes, and the electroless tin Plated.

<Measurement method>

Thus, the presence of overplating of tin in a 50 탆 pitch pattern on an electrolessly tin plated MSAP substrate was investigated. The results are shown in Figs. 2 to 8 and Table 2.

The deposition rate of the MSAP substrate on which the tin coating was formed was measured by a conventional measurement method using a CMI 1500 manufactured by BOWMAN KOREA as a fluorescent X-ray analyzer. The deposition rate was 2.2 탆 / 20 min, The precipitation rate of 3.3 탆 / 60 min or more was confirmed.

As a result of observing the voids of the specimen, none was observed, as shown in Figs. 3A to 3D. FIG. 3 is a photograph showing that voids and overflow phenomenon are not observed when high-speed plating is performed using the electroless plating solution according to an embodiment of the present invention for 20 minutes and 60 minutes, and FIG. Shows that when the coating is performed at a working temperature of 68 ° C for 20 minutes using a high-speed plating solution, the appearance is satisfied and a void phenomenon is not observed. (b) The photograph shows that when the high-speed plating solution is used, plating is performed at a working temperature of 68 ° C for 60 minutes, the appearance is satisfied, and the void phenomenon is not observed. According to the diagrams (c) and (d), it can be seen that overflowing phenomenon is not observed when performing the plating at a working temperature of 68 ° C for 60 minutes.

Figs. 4 to 7 are photographs showing the appearance when the components of the high-speed plating solution have an improper content range, Fig. 4 is a plating solution of Comparative Example 2, Fig. 5 is a plating solution of Comparative Example 3, Fig. 6 is a plating solution of Comparative Example 4 And Fig. 7 corresponds to the case of using the plating solution of Comparative Example 5, respectively.

division Plating thickness (탆) Overflowing Exterior presence or absence of void Remarks Example 1 2.270 Not occurring Good Not occurring Good plating thickness Comparative Example 1
1.581 Occur Good Occur Poor plating thickness Comparative Example 2
1.019 Not occurring Visual defects Occur Poor plating thickness Comparative Example 3 2.297 Occur Surface roughness Not occurring Good plating thickness Comparative Example 4 1.675 Occur Surface void generation Occur Poor plating thickness Comparative Example 5 2.174 Occur Good Occur Deep thickness variation Comparative Example 6 2.404 Occur Surface roughness Not occurring Good plating thickness Example 2 2.644 Not occurring Good Not occurring Good plating thickness

As shown in Table 2, in the case of Examples 1 and 2 using the composition of the present invention, not only the thickness plating in the electroless tin plating can be obtained in a short time, but also the corrosion of the lower metal layer, which causes defects in the form of voids or overflowing, , Respectively.

On the other hand, in the case of Comparative Example 1 in which the conventional low-speed plating solution was used and high-speed plating was performed, it was confirmed that voids were formed as shown in Fig. 1, and overflow phenomenon was observed at the same time (see Figs.

Further, in the case of Comparative Examples 2 to 5 in which the content of the component was out of the proper range, voids, appearance of rough surface, occurrence of overflowing, etc. were observed as shown in Figs.

In the case of Comparative Example 6 in which high-speed plating was performed despite the inappropriate composition, rough surface appearance was seriously observed, as shown in Fig.

Claims (14)

An electroless tin plating liquid comprising a tin source of tin, an antioxidant, a surfactant and an organic sulfonic acid, wherein the total amount of the antioxidant is from 20 g / L to 500 g / L or less based on 1 L of the electroless tin plating solution as a whole ,
(1) to (2): w / v of formula (3) in the ratio of 1: 0.5 to 1: 0.5 to 1 Electroless tin plating solution:
[Chemical Formula 1]

(2)

(3)

R ¹ and R ² are each a primary amine group (NH ₂ ) and R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² (OH), an alkyl group having 1 to 20 carbon atoms, a primary amine group (NH ₂ ), or a carboxyl group (COOH), wherein R ³ , R ⁴ , R ⁵ and R ⁶ are each independently selected from the group consisting of hydrogen, R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² each have two or more functional groups selected from a primary amine group (NH ₂ ) and a carboxyl group (COOH). delete The method according to claim 1,
Wherein each of R ³ , R ⁴ , R ⁵ and R ⁶ is hydrogen, a hydroxyl group (OH), an alkyl group having 1 to 20 carbon atoms, a primary amine group (NH ₂ ), and a carboxyl group (COOH) . The method according to claim 1,
Wherein R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ^{12 each} independently have two kinds of carboxyl groups (COOH), two kinds of hydroxyl groups (OH) Plating solution. The method according to claim 1,
Wherein the compound represented by Formula 1, the compound represented by Formula 2, and the compound represented by Formula 3 are contained in a total content of more than 125 g / L and not more than 500 g / L. The method according to claim 1,
The antioxidant may be at least one selected from the group consisting of catechol, resorcinol, phloroglucinol, pyrogallol, dihydroxynaphthalene, cresol, hydrazine, hypophosphoric acid, Tin plating solution. The method according to claim 1,
Wherein the plating solution comprises a surfactant in a range of 0.01 to 100 g / L, and the surfactant is selected from the group consisting of alkane, polyalkylene glycol phenyl ether, phenol, naphthol, bisphenol, arylalkylphenol, sorbitan ester and aliphatic amide Wherein the electroless tin plating solution is at least one selected from the group consisting of copper, 8. The method of claim 7,
Wherein the polyalkylene glycol phenyl ether is a compound represented by the following formula (4): &lt; EMI ID =
[Chemical Formula 4]

Wherein R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ are independently hydrogen, a hydroxyl group (OH) or an alkyl group having 1 to 20 carbon atoms, and n is 6 to 10. 9. The method of claim 8,
Wherein R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ are an alkyl group having 1 to 20 carbon atoms and R ¹⁸ is hydrogen. The method according to claim 1,
Wherein the plating solution contains an organic sulfonic acid in a range of more than 150 g / L to less than 300 g / L, and the organic sulfonic acid is selected from the group consisting of methanesulfonic acid, ethanesulfonic acid, 1-propanesulfonic acid, 2- At least one member selected from the group consisting of copper, tin, and nickel. The method according to claim 1,
Wherein the plating solution comprises a first tin salt as a divalent tin source in an amount of 1 g / L to 50 g / L, wherein the first tin salt is selected from the group consisting of tin chloride, tin sulfate, tin pyrophosphate, tin citrate, tin oxalate, Tin, tin 1-propanesulfonate, tin pyrophosphate, tin methano sulfonate, and methane tartaric acid. 12. The method according to any one of claims 1 to 11,
The plating solution had a tin coating thickness of 2.07 to 2.77 μm measured at 20 minutes after electroless plating at 60 to 90 ° C. and a tin coating thickness of 2.7 to 4.0 μm measured at 60 minutes, Wherein the thickness of the film is 7 to 9 占 퐉 and the tin coatings are formed without overplating or void. An electronic component comprising a tin coating,
Wherein the tin coating is an electroless tin plating solution according to any one of claims 1 to 3, electroless-plated the substrate for electronic parts at 60 to 90 캜, and the tin coating Wherein the thickness of the tin coating film measured at 60 minutes is 2.7 to 4.0 占 퐉 and the thickness of the tin coating film measured at 180 minutes is 7 to 9 占 퐉 and the tin coating films are overplating, Or voids. &Lt; RTI ID = 0.0 &gt; [0002] &lt; / RTI &gt; 14. The method of claim 13,
The substrate for electronic components may be a modified semi- additive process (MSAP) substrate, a semi- additive process (SAP) substrate, an advanced mod- ified semi- additive process (AMSAP) substrate, a full additive process (FAP) In electronic components.

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