CN110983305A

CN110983305A - Application of quaternary ammonium salt compound in preparation of composition for inhibiting chemical plating and diffusion plating and preparation method of metal layer

Info

Publication number: CN110983305A
Application number: CN201911314282.1A
Authority: CN
Inventors: 黎小芳; 李小兵; 陈光辉; 万会勇; 席道林; 郭志伟
Original assignee: Guangdong Toneset Science & Technology Co ltd
Current assignee: Guangdong Toneset Science & Technology Co ltd
Priority date: 2019-12-19
Filing date: 2019-12-19
Publication date: 2020-04-10
Anticipated expiration: 2039-12-19
Also published as: CN110983305B

Abstract

The invention relates to application of a quaternary ammonium salt compound in preparation of a composition for inhibiting chemical plating and diffusion and a preparation method of a metal layer. The quaternary ammonium salt compound has a structure shown in a general formula (I), so that the quaternary ammonium salt compound and palladium ions can generate competitive adsorption at the edge and the corner of the metal substrate, the deposition of a palladium simple substance at the edge and the corner of the metal substrate is reduced, and the occurrence of a diffusion plating phenomenon is inhibited. Meanwhile, the nitrogen atoms are positively charged and in an electron-deficient state, and can adsorb electrons robbed by the edges and corners of the metal substrate and palladium ions, so that the deposition of a palladium simple substance at the edges and corners of the metal substrate is inhibited, and the occurrence of a diffusion plating phenomenon is further inhibited.

Description

Application of quaternary ammonium salt compound in preparation of composition for inhibiting chemical plating and diffusion plating and preparation method of metal layer

Technical Field

The invention relates to the technical field of chemical plating, in particular to application of a quaternary ammonium salt compound in preparing a composition for inhibiting chemical plating and diffusion plating and a preparation method of a metal layer.

Background

In the processing process of the printed circuit board and the wafer, surface treatment is an effective step for improving the performance of the circuit board and the wafer, and the conductivity, the flatness and the like of the circuit board and the wafer can be effectively improved through the surface treatment. In the surface treatment process, chemical plating is widely used due to the characteristics of uniform plating layer, small pinholes, capability of depositing on a non-conductor and the like. The electroless nickel-gold or nickel-palladium-gold process integrates the functions of solderability, contactability, routing, heat dissipation and the like, and has become one of the mainstream of surface treatment of circuit boards and wafers. For example, a thin palladium layer is formed on a metal substrate (such as a copper substrate) on the surface of a circuit board or a wafer by an electroless nickel-gold or nickel-palladium-gold process as a catalytic catalyst for nickel deposition, thereby producing a non-electrolytic deposition of nickel to improve the performance of the circuit board or the wafer. However, this electroless nickel plating method generally causes the elemental palladium to deposit not only on the metal substrate, but also on the edges of the metal substrate. The deposited palladium is difficult to remove effectively, so that subsequent nickel is deposited on the metal substrate and also deposited on the plate surface near the metal substrate, namely, the phenomenon of 'diffusion plating' occurs. When the diffusion phenomenon occurs, a point-like gold deposit is generated on the circuit board surface or the wafer, and a short circuit is generated even when the line width is increased and the line distance is decreased, particularly in a high-density circuit with the line width and the line distance of about 35 μm or less. This is unacceptable during processing of circuit boards and wafers.

Therefore, it is necessary to prevent the occurrence of the phenomenon of the diffusion plating during the electroless plating process of the circuit board and the wafer. The traditional prevention method is to prevent the occurrence of the diffusion plating phenomenon by shortening the activation time of the circuit board and the wafer in the chemical nickel plating process, but the activation is insufficient due to the shortening of the activation time, the problem of 'plating leakage' is caused, and the adverse effect is also caused on the performance of the circuit board and the wafer.

Disclosure of Invention

Based on this, an object of the present invention is to provide a use of a quaternary ammonium salt compound for producing a composition for suppressing electroless plating bleeding, the quaternary ammonium salt compound having a structure represented by general formula (i):

wherein B is a five-membered ring having 1 to 2 nitrogen atoms or a six-membered ring having 1 to 2 nitrogen atoms;

r1 and R2 are independently selected from substituted or unsubstituted alkyl with 1-20 carbon atoms;

r4 is selected from hydrogen, cyano, hydroxyl, carboxyl, amino, nitro, sulfonic group, substituted or unsubstituted alkyl with 1-12 carbon atoms, or substituted or unsubstituted alkoxy with 1-12 carbon atoms;

when A appears, A is a benzene ring, A and B form a condensed ring, and R3 is selected from hydrogen, halogen group, cyano group, hydroxyl group, carboxyl group, amino group, nitro group, sulfonic group, substituted or unsubstituted alkyl with 1-12 carbon atoms, or substituted or unsubstituted alkoxy with 1-12 carbon atoms; when A is absent, B is a five-membered ring having 1 to 2 nitrogen atoms or a six-membered ring having 1 to 2 nitrogen atoms, and B is not a pyridine ring;

n is 1 or 2; x is an anion.

In one embodiment, R1 and R2 are independently selected from substituted alkyl with 1-20 carbon atoms, wherein the substituent on the alkyl is hydrogen, halogen, cyano, hydroxyl, carboxyl, amino, nitro, sulfonic group, substituted or unsubstituted aryl, or substituted or unsubstituted alkoxy with 1-4 carbon atoms.

In one embodiment, R3 is selected from a substituted alkyl group having 1-12 carbon atoms or a substituted alkoxy group having 1-12 carbon atoms, wherein the substituents on the alkyl group and the alkoxy group are hydroxyl, carboxyl, amino, nitro, sulfonic acid group or alkoxy group having 1-4 carbon atoms.

In one embodiment, R4 is selected from a substituted alkyl group with 1-12 carbon atoms or an alkoxy group with 1-12 carbon atoms, wherein the substituent on the alkyl group and the alkoxy group is a hydroxyl group, a halogen group, a cyano group, a carboxyl group, an amino group, a nitro group, a sulfonic group or an alkoxy group with 1-4 carbon atoms.

In one embodiment, X is selected from fluoride, chloride, bromide, iodide, sulfate, acetate, or alkyl sulfate.

It is another object of the present invention to provide a composition for inhibiting electroless plating bleeding comprising a palladium source, an acid, a solvent, and at least one quaternary ammonium salt compound as described in any of the above embodiments.

In one embodiment, the concentration of the quaternary ammonium salt compound in the composition is 0.001g/L to 5g/L, the concentration of palladium ions provided by the palladium source is 0.001g/L to 5g/L, and the concentration of the acid is 5g/L to 200 g/L.

It is another object of the present invention to provide a method for preparing a metal layer by electroless plating, which comprises the step of treating a product to be processed by adding the quaternary ammonium salt compound described in any of the above embodiments during activation before performing electroless plating.

In one embodiment, the method comprises the step of treating a product to be processed with the composition for inhibiting electroless plating bleeding described in any of the above embodiments during activation prior to electroless plating.

Another object of the present invention is to provide a printed circuit board or a wafer, which includes a metal layer prepared by the method as described in any of the above embodiments.

The quaternary ammonium salt compound is used for preparing the composition for inhibiting the chemical plating and the penetration. The quaternary ammonium salt compound can generate competitive adsorption with palladium ions at the edge and the corner of the metal substrate, and reduces or even avoids the deposition of a palladium simple substance at the edge and the corner of the metal substrate, thereby inhibiting the occurrence of a diffusion plating phenomenon and enabling chemical plating metal to be more uniform. Meanwhile, nitrogen atoms in the quaternary ammonium salt compound are positively charged and in an electron-deficient state, and can adsorb electrons robbed by the edges and corners of the metal substrate and palladium ions, so that the deposition of a palladium simple substance at the edges and corners of the metal substrate is inhibited, and the occurrence of a diffusion plating phenomenon is further inhibited.

The composition for inhibiting the chemical plating and the diffusion comprises a palladium source, an acid, a solvent and the quaternary ammonium salt compound, and is used for treating a product to be processed before chemical plating processing, so that a uniform palladium layer is formed on a metal substrate of the product to be processed, and the deposition of a palladium simple substance on the edge and the corner of the metal substrate is effectively reduced. And then, after the product to be processed is subjected to chemical plating, a required metal layer can be formed on the metal substrate, so that the occurrence of a diffusion plating phenomenon is reduced.

Drawings

Fig. 1 is a graph showing the effect of electroless nickel-gold treatment on a printed circuit board after activation treatment using the composition prepared in example 1.

Fig. 2 is a graph showing effects of a printed circuit board after activation treatment using the composition prepared in comparative example 1 after electroless nickel-gold treatment.

Detailed Description

In order that the invention may be more fully understood, reference will now be made to the accompanying examples. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In the following detailed description, unless otherwise specified, all conventional methods are used; the raw materials, reagents, and the like used in the following embodiments are all commercially available products unless otherwise specified.

The "quaternary ammonium salt compound" according to the present invention is a compound which has been disclosed, and can be purchased from commercial sources, for example, Sigma-Aldrich (Sigma Aldrich) company or Akzo Nobel (aksunobel) company, or prepared by a publicly available literature.

One embodiment of the present invention provides an application of a quaternary ammonium salt compound in preparing a composition for inhibiting electroless plating and diffusion, wherein the quaternary ammonium salt compound has a structure represented by general formula (i):

n is 1 or 2; x is an anion.

The diffusion plating phenomenon occurs when the metal substrate of the printed circuit board and the wafer is chemically plated to form a metal layer, because the phenomenon of electron gain and loss exists in the contact process of the metal substrate and palladium ions, namely the metal substrate loses electrons to form corresponding metal ions to be separated from the metal substrate, and the electrons obtained by the palladium ions are changed into a palladium simple substance. During the process of losing electrons of the metal substrate, the lost electrons move towards the edge and the corner of the metal substrate due to the existence of the tip effect. At this time, the edges and corners of the metal substrate are enriched with more electrons, and then palladium ions are attracted to move towards the edges and corners of the metal substrate, and the palladium ions are deposited on the edges and corners of the metal substrate after obtaining the electrons. In the subsequent electroless metal plating process, metal is deposited on the edges and corners of the metal substrate, and the phenomenon of diffusion occurs.

The quaternary ammonium salt compound can generate competitive adsorption with palladium ions at the edge and the corner of the metal substrate, and reduces or even avoids the deposition of a palladium simple substance at the edge and the corner of the metal substrate, thereby inhibiting the occurrence of a diffusion plating phenomenon and enabling chemical plating metal to be more uniform. Meanwhile, nitrogen atoms in the quaternary ammonium salt compound are positively charged and in an electron-deficient state, and can adsorb electrons robbed by the edges and corners of the metal substrate and palladium ions, so that the deposition of a palladium simple substance at the edges and corners of the metal substrate is inhibited, and the occurrence of a diffusion plating phenomenon is further inhibited.

Preferably, R1 and R2 are independently selected from substituted alkyl groups having 1 to 20 carbon atoms, wherein the substituents on the alkyl groups are hydrogen, halogen, cyano, hydroxyl, carboxyl, amino, nitro, sulfonic acid, substituted or unsubstituted aryl, or substituted or unsubstituted alkoxy groups having 1 to 4 carbon atoms.

More preferably, R1 and R2 are independently selected from substituted or unsubstituted alkyl groups having 1-8 carbon atoms. Specifically, when R1 and R2 are independently selected from substituted alkyl groups having 1 to 8 carbon atoms, the substituents on the substituted alkyl groups are hydrogen, hydroxyl, carboxyl, amino, nitro, sulfonic acid, substituted or unsubstituted aryl, and substituted or unsubstituted alkoxy groups having 1 to 4 carbon atoms.

In a specific example, R3 is selected from substituted alkyl with 1-12 carbon atoms or substituted alkoxy with 1-12 carbon atoms, wherein, the substituent on the alkyl and the alkoxy is hydroxyl, carboxyl, amino, nitro, sulfonic group or alkoxy with 1-4 carbon atoms.

Preferably, R3 is selected from a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted alkoxy group having 1 to 4 carbon atoms. When R3 is selected from a substituted alkyl group having 1 to 4 carbon atoms or a substituted alkoxy group having 1 to 4 carbon atoms, the substituent on the substituted alkyl group is a hydroxyl group, a carboxyl group, an amino group, a nitro group, a sulfonic group or an alkoxy group having 1 to 4 carbon atoms, and the substituent on the substituted alkoxy group is a hydroxyl group, a carboxyl group, an amino group, a nitro group, a sulfonic group or an alkoxy group having 1 to 4 carbon atoms.

In a specific example, R4 is selected from substituted alkyl with 1-12 carbon atoms or alkoxy with 1-12 carbon atoms, wherein, the substituent on the alkyl and alkoxy is hydroxyl, halogen, cyano, carboxyl, amino, nitro, sulfonic group or alkoxy with 1-4 carbon atoms.

Preferably, R4 is selected from substituted or unsubstituted alkyl with 1-4 carbon atoms and substituted or unsubstituted alkoxy with 1-4 carbon atoms. When R4 is selected from a substituted alkyl group having 1 to 4 carbon atoms or a substituted alkoxy group having 1 to 4 carbon atoms, the substituent on the substituted alkyl group is a hydroxyl group, a carboxyl group, an amino group, a nitro group, a sulfonic group or an alkoxy group having 1 to 4 carbon atoms, and the substituent on the substituted alkoxy group is a hydroxyl group, a carboxyl group, an amino group, a nitro group, a sulfonic group or an alkoxy group having 1 to 4 carbon atoms.

In a particular example, X is selected from fluoride, chloride, bromide, iodide, sulfate, acetate, or alkyl sulfate. As a preferred mode of the alkylsulfate ion, the alkylsulfate ion is CH₃SO₄ ^-Or C₂H₅SO₄ ^-。

As the compound having the structure represented by the general formula (I), the quaternary ammonium salt compound may be, but is not limited to, 1-ethyl-3-methylimidazolium methanesulfonate, 1-butyl-2, 3-dimethylimidazolium chloride salt, 2- [1- (2-hydroxyethyl) -2-octadecyl-4, 5-dihydroimidazol-1-azonium ion-1-yl ] ethanolic chloride salt, 1- (2-chloroethyl) -3-methylbenzimidazole-3-azonium ion chloride salt, 1-acetic acid quinoline-1 azonium chloride salt, 2- (2-chloroethyl) isoquinoline-2-azonium chloride salt, 1-ethyl-1-methylpyrrolidine-1-azonium bromide salt or N-methyl-N-benzylpiperidine chloride salt.

The invention also provides a composition for inhibiting the chemical plating and the plating, which comprises a palladium source, an acid, a solvent and at least one quaternary ammonium salt compound with the structure shown in the general formula (I).

In the composition for inhibiting the electroless plating penetration, the concentration of the quaternary ammonium salt compound is 0.001g/L to 5g/L, the concentration of palladium ions provided by a palladium source is 0.001g/L to 5g/L, and the concentration of acid is 5g/L to 200 g/L. Wherein the concentration of palladium ions provided by the palladium source is 0.001g/L to 5g/L, which refers to the concentration of palladium ions in the composition.

Preferably, the palladium source provides palladium ions at a concentration of 0.003g/L to 0.5g/L, more preferably, the palladium source provides palladium ions at a concentration of 0.005g/L to 0.1g/L, and even more preferably, the palladium source provides palladium ions at a concentration of 0.005g/L to 0.05 g/L. Preferably, the concentration of the acid is 10g/L to 100 g/L.

The composition comprises a palladium source, acid, a solvent and the quaternary ammonium salt compound, and is used for treating a product to be processed before chemical plating processing, so that a uniform palladium layer is formed on a metal substrate of the product to be processed, and the deposition of a palladium simple substance on the edge and the corner of the metal substrate is effectively reduced. And then, after the product to be processed is subjected to chemical plating, a required metal layer can be formed on the metal substrate, so that the occurrence of a diffusion plating phenomenon is reduced.

In one particular example, the palladium source is a soluble palladium salt and/or a complex of palladium. In a preferred embodiment, the palladium source is one or more of palladium sulfate, palladium chloride, palladium acetate, palladium nitrate and tetraamminepalladium sulfate.

In a specific example, the acid is an organic acid and/or an inorganic acid. Preferably, the acid is a mixture of one or more of sulfonic acid, chloroacetic acid, sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid.

In addition to the quaternary ammonium salt compound and the composition for inhibiting electroless plating bleed, an embodiment of the present invention also provides a method for preparing the composition for inhibiting electroless plating bleed. The preparation method of the composition comprises the following steps:

mixing a palladium source, acid and a solvent to obtain a mixed solution;

and mixing the quaternary ammonium salt compound with the mixed solution.

The solvent is preferably water during the preparation of the composition. Adding a palladium source and an acid into water respectively, and stirring to form a uniform mixed solution of a palladium salt, the acid and the water. And then adding the quaternary ammonium salt compound into the mixed solution, and stirring and mixing to obtain the uniform composition for inhibiting the chemical plating and the diffusion plating.

The embodiment of the invention also provides application of the composition for inhibiting the chemical plating diffusion plating as an activating solution in chemical plating. In the processing technology of chemical plating, the composition is used as an activating solution to treat a product to be processed before chemical plating, so that the occurrence of a diffusion plating phenomenon can be effectively inhibited.

The embodiment of the invention also provides a method for preparing the metal layer by chemical plating. The preparation method comprises the step of adding the quaternary ammonium salt compound to treat a product to be processed in the activation process before chemical plating.

As a preferable mode, the production method comprises a step of treating a product to be processed with the above-mentioned electroless plating bleeding inhibition composition before electroless plating.

The embodiment of the invention also provides a printed circuit board which comprises the metal layer prepared by the method. The problem of diffusion plating on the surface of the printed circuit board is well inhibited, the line width spacing of the circuit board is stable and uniform, the surface of the circuit board is not stained with gold in a dotted manner, and the performance is stable.

The embodiment of the invention also provides a wafer which comprises the metal layer prepared by the method. The wafer has more excellent and stable performance because the diffusion phenomenon is effectively inhibited.

The following are specific examples. In the examples, the CAS number refers to a registration number assigned to a chemical substance by chemical abstracts.

Example 1

The quaternary ammonium salt compound in this example was 1-ethyl-3-methylimidazolium methanesulfonate (CAS number: 516474-01-4). The raw materials of the composition for inhibiting the chemical plating and the diffusion plating are palladium sulfate, sulfuric acid, 1-ethyl-3-methylimidazole methanesulfonate and pure water. Wherein the concentration of palladium ions is 0.1g/L, the concentration of sulfuric acid is 50g/L, and the concentration of 1-ethyl-3-methylimidazole methanesulfonate is 0.15 g/L.

The preparation method of the composition for inhibiting electroless plating and diffusion in the embodiment comprises the following steps: adding sulfuric acid into pure water, adding palladium sulfate, and stirring until the palladium sulfate is completely dissolved to obtain a mixed solution. Then dissolving 1-ethyl-3-methylimidazole methanesulfonate in pure water, adding the mixture of 1-ethyl-3-methylimidazole methanesulfonate and pure water into the mixed solution, and uniformly stirring. The composition for suppressing the electroless plating bleeding in the present example was obtained.

Example 2

The quaternary ammonium salt compound in this example was 1-butyl-2, 3-dimethylimidazolium chloride salt (CAS number: 98892-75-2). The raw materials of the composition for inhibiting the chemical plating and the diffusion plating are palladium sulfate, sulfuric acid, 1-butyl-2, 3-dimethyl imidazole chloride salt and pure water. Wherein the concentration of palladium ions is 0.012g/L, the concentration of sulfuric acid is 20g/L, and the concentration of 1-butyl-2, 3-dimethyl imidazole chloride salt is 0.05 g/L.

The preparation method of the composition for inhibiting electroless plating and diffusion in the embodiment comprises the following steps: adding sulfuric acid into pure water, adding palladium sulfate, and stirring until the palladium sulfate is completely dissolved to obtain a mixed solution. Then dissolving 1-butyl-2, 3-dimethyl imidazole chloride salt in pure water, adding the mixture of the 1-butyl-2, 3-dimethyl imidazole chloride salt and the pure water into the mixed solution, and stirring uniformly. The composition for suppressing the electroless plating bleeding in the present example was obtained.

Example 3

In this example, the quaternary ammonium salt compound was 2- [1- (2-hydroxyethyl) -2-octadecyl-4, 5-dihydroimidazol-1-azonian-1-yl ] ethanolic chloride salt (CAS number: 6265-43-6). The raw materials of the composition for inhibiting the chemical plating and the diffusion plating are palladium sulfate, sulfuric acid, 2- [1- (2-hydroxyethyl) -2-octadecyl-4, 5-dihydroimidazole-1-azoniaion-1-radical ] ethanol chloride and pure water. Wherein the concentration of palladium ions is 0.003g/L, the concentration of sulfuric acid is 5g/L, and the concentration of 2- [1- (2-hydroxyethyl) -2-octadecyl-4, 5-dihydroimidazole-1-azonian ion-1-yl ] ethanol chloride is 0.02 g/L.

The preparation method of the composition for inhibiting electroless plating and diffusion in the embodiment comprises the following steps: adding sulfuric acid into pure water, adding palladium sulfate, and stirring until the palladium sulfate is completely dissolved to obtain a mixed solution. Then 2- [1- (2-hydroxyethyl) -2-octadecyl-4, 5-dihydroimidazole-1-azonian ion-1-yl ] ethanol chloride is dissolved in pure water, and then the mixture of the 2- [1- (2-hydroxyethyl) -2-octadecyl-4, 5-dihydroimidazole-1-azonian ion-1-yl ] ethanol chloride and the pure water is added into the mixed solution and stirred uniformly. The composition for suppressing the electroless plating bleeding in the present example was obtained.

Example 4

The quaternary ammonium salt compound in this example was 1- (2-chloroethyl) -3-methylbenzimidazole-3-azonium chloride salt (CAS number: 73698-39-2). The raw materials of the composition for inhibiting the chemical plating and the diffusion plating are palladium chloride, sulfuric acid, 1- (2-chloroethyl) -3-methylbenzimidazole-3-azonium chloride and pure water. Wherein the concentration of palladium ions is 0.02g/L, the concentration of sulfuric acid is 25g/L, and the concentration of 1- (2-chloroethyl) -3-methylbenzimidazole-3-azonian ion chloride salt is 0.03 g/L.

The preparation method of the composition for inhibiting electroless plating and diffusion in the embodiment comprises the following steps: adding sulfuric acid into pure water, adding palladium chloride, and stirring until the palladium chloride is completely dissolved to obtain a mixed solution. Then dissolving 1- (2-chloroethyl) -3-methylbenzimidazole-3-azonia ion chloride salt in pure water, adding the mixture of the 1- (2-chloroethyl) -3-methylbenzimidazole-3-azonia ion chloride salt and the pure water into the mixed solution, and uniformly stirring. The composition for suppressing the electroless plating bleeding in the present example was obtained.

Example 5

The quaternary ammonium salt compound in this example was 1-acetic acid quinoline-1 azonium chloride salt (CAS number: 46273-39-6). The raw materials of the composition for inhibiting the chemical plating and the diffusion plating are palladium acetate, methanesulfonic acid, 1-acetic acid quinoline-1 azonium chloride and pure water. Wherein the concentration of palladium ions is 0.03g/L, the concentration of methanesulfonic acid is 50g/L, and the concentration of 1-acetic acid quinoline-1 azonium chloride is 0.01 g/L.

The preparation method of the composition for inhibiting electroless plating and diffusion in the embodiment comprises the following steps: adding methanesulfonic acid into pure water, adding palladium acetate, and stirring until the palladium acetate is completely dissolved to obtain a mixed solution. Then dissolving 1-acetic acid quinoline-1 azonium ion chloride salt in pure water, adding the mixture of the 1-acetic acid quinoline-1 azonium ion chloride salt and the pure water into the mixed solution, and stirring uniformly. The composition for suppressing the electroless plating bleeding in the present example was obtained.

Example 6

In this example, the quaternary ammonium salt compound was 2- (2-chloroethyl) isoquinoline-2-azonium chloride salt (CAS number: 7041-33-0). The raw materials of the composition for inhibiting the chemical plating and the diffusion plating are palladium nitrate, sulfuric acid, 2- (2-chloroethyl) isoquinoline-2-azonium chloride salt and pure water. Wherein the concentration of palladium ions is 0.03g/L, the concentration of sulfuric acid is 50g/L, and the concentration of 2- (2-chloroethyl) isoquinoline-2-azonium chloride salt is 0.01 g/L.

The preparation method of the composition for inhibiting electroless plating and diffusion in the embodiment comprises the following steps: adding sulfuric acid into pure water, adding palladium nitrate, and stirring until the palladium nitrate is completely dissolved to obtain a mixed solution. Then 2- (2-chloroethyl) isoquinoline-2-azonium ion chloride is dissolved in pure water, and then the mixture of the 2- (2-chloroethyl) isoquinoline-2-azonium ion chloride and the pure water is added into the mixed solution and stirred uniformly. The composition for suppressing the electroless plating bleeding in the present example was obtained.

Example 7

In this example, the quaternary ammonium salt compound was 1-ethyl-1-methylpyrrolidine-1-azonium bromide (CAS number: 69227-51-6). The raw materials of the composition for inhibiting the chemical plating and the diffusion plating are palladium chloride, hydrochloric acid, 1-ethyl-1-methylpyrrolidine-1-azonium ion bromine salt and pure water. Wherein the concentration of palladium ions is 0.5g/L, the concentration of hydrochloric acid is 200g/L, and the concentration of 1-ethyl-1-methylpyrrolidine-1-azonium bromide is 5 g/L.

The preparation method of the composition for inhibiting electroless plating and diffusion in the embodiment comprises the following steps: adding hydrochloric acid into pure water, adding palladium chloride, and stirring until the palladium chloride is completely dissolved to obtain a mixed solution. Then dissolving 1-ethyl-1-methylpyrrolidine-1-azonium ion bromine salt in pure water, adding the mixture of the 1-ethyl-1-methylpyrrolidine-1-azonium ion bromine salt and the pure water into the mixed solution, and uniformly stirring. The composition for suppressing the electroless plating bleeding in the present example was obtained.

Example 8

The quaternary ammonium salt compound in this example was N-methyl-N-benzylpiperidine chloride salt (CAS number: 13127-28-1). The raw materials of the composition for inhibiting the chemical plating and the diffusion plating are palladium sulfate, sulfuric acid, N-methyl-N-benzyl piperidine chloride salt and pure water. Wherein the concentration of palladium ions is 0.03g/L, the concentration of sulfuric acid is 50g/L, and the concentration of N-methyl-N-benzylpiperidine chloride salt is 0.05 g/L.

The preparation method of the composition for inhibiting electroless plating and diffusion in the embodiment comprises the following steps: adding sulfuric acid into pure water, adding palladium sulfate, and stirring until the palladium sulfate is completely dissolved to obtain a mixed solution. Then dissolving the N-methyl-N-benzyl piperidine chloride salt in pure water, adding the mixture of the N-methyl-N-benzyl piperidine chloride salt and the pure water into the mixed solution, and stirring uniformly. The composition for suppressing the electroless plating bleeding in the present example was obtained.

Comparative example 1

This comparative example differs from example 1 in that the composition does not contain a quaternary ammonium salt compound.

Test example 1

Printed circuit boards and wafers having copper traces are processed according to the current conventional electroless nickel-gold process, and nickel and gold layers are plated on the copper traces. Among them, the printed circuit boards and wafers were treated with the compositions of examples 1 to 8 and comparative example 1 in the activation step as follows:

treating the materials: the specification of the printed circuit board is 11.5cm multiplied by 12cm, and the FR4 material copper-clad circuit board has the line width of 35 mu m and the line distance of 35 mu m. The wafer specification is a silicon disk with a diameter of 2cm, a line width of 25 μm and a line pitch of 10 μm.

The process comprises the following steps: degreasing → water washing → microetching → water washing → presoaking → activation → water washing → nickel deposition → water washing → gold deposition → water washing → blow-drying, wherein the water washing is to rinse the substrate with deionized water for 1 minute.

(1) Oil removal: the oil removal agent TS-acid clean 6189 product of Guangdong Shuo science and technology Limited is used, the operation temperature is 35 ℃, and the treatment time is 5 minutes.

(2) Micro-etching: the microetching agent consists of 100g/L sodium persulfate and 2% (v/v) sulfuric acid, and the operating temperature is 30 ℃. The processing time is 2 minutes for the printed circuit board and 30 seconds for the wafer.

(3) Pre-dipping: 1% sulfuric acid is adopted for treatment, and a water bath sleeve is arranged outside the presoaking tank, so that the temperature of the presoaking tank can be reduced to 20 ℃, and the treatment time is 2 minutes.

(4) And (3) activation: the activating solutions prepared in examples 1-8 and comparative example 1 were used, the operating temperature was 26 ℃, the activation time of palladium on copper surface was about 2 minutes, and the activation time of the examples of the present invention was extended to 8 minutes, so as to show the effect of the composition of the present invention in suppressing the plating bleeding.

(5) Depositing nickel: the nickel deposition is carried out by chemical deposition nickel gold 5183LMP series of medicinal liquid of Guangdong Shuoji, the operation temperature is 82 deg.C, and the treatment time is 25 minutes.

(6) And (3) palladium precipitation: palladium plating is carried out by using a palladium solution containing 0.04mol/L of palladium chloride, 0.5mol/L of ethylenediamine, 0.05mol/L of ethylenediamine tetraacetic acid and 0.2mol/L of sodium hypophosphite, wherein the pH value is 6.5, the temperature is 55 ℃, and the time is 10 minutes.

(7) Gold precipitation: the immersion gold 5185 series of medicinal liquid is used for immersion gold precipitation by Guangdong Shuojio technology Co., Ltd, the operation temperature is 85 ℃, and the treatment time is 8 minutes.

(8) Drying: drying with an air duct at a temperature of about 65 ℃.

Testing indexes are as follows: and observing the diffusion plating conditions of the nickel layer and the gold layer of the copper circuit on all the circuit boards and wafers which are subjected to electroless nickel and gold under a metallographic microscope. In the test, the ratio of the line spacing after electroless nickel-gold plating to the original line spacing is used for representing the diffusion plating condition of the copper circuit, the numerical value is larger, the line spacing change is smaller, the diffusion plating condition is more slight, and otherwise, the diffusion plating condition is more serious.

The compositions for inhibiting copper electroless plating of examples 1-8 and comparative example 1 were used to treat 1 piece of printed circuit board and 1 piece of wafer and are numbered 1 and 2 respectively, for example, the sample treated with the composition of example 1 has printed circuit board number 1-1 and wafer number 1-2, and so on, and the printed circuit board treated with the composition of comparative example 1 has printed circuit board number 9-1 and wafer number 9-2, and the specific test results are shown in Table 1.

TABLE 1

As can be seen from the above table, the percentage of the wire spacing/the original wire spacing in examples 1 to 8 is significantly higher than that in comparative example 1 after electroless nickel-gold plating, which illustrates that the compositions in examples 1 to 8 can effectively inhibit the diffusion plating of electroless plating.

The effect of the printed circuit board after electroless nickel-gold in example 1 is shown in fig. 1. The effect of the printed circuit board after electroless nickel-gold in comparative example 1 is shown in fig. 2. The variation of the line width and the line distance in fig. 1 is obviously smaller than that in fig. 2, the surface of the printed circuit board in fig. 1 is hardly subjected to the diffusion plating phenomenon, and the surface of the printed circuit board in fig. 2 is obviously subjected to the diffusion plating phenomenon. It is demonstrated that the composition of example 1 is effective in suppressing the bleeding of electroless plating.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The application of a quaternary ammonium salt compound in preparing a composition for inhibiting chemical plating and diffusion is characterized in that: the quaternary ammonium salt compound has a structure represented by general formula (I):

n is 1 or 2; x is an anion.

2. The use of claim 1, wherein: r1 and R2 are independently selected from substituted alkyl with 1-20 carbon atoms, wherein the substituent on the alkyl is hydrogen, halogen group, cyano group, hydroxyl group, carboxyl group, amino group, nitro group, sulfonic group, substituted or unsubstituted aryl, or substituted or unsubstituted alkoxy with 1-4 carbon atoms.

3. The use of claim 1, wherein: r3 is selected from substituted alkyl with 1-12 carbon atoms or substituted alkoxy with 1-12 carbon atoms, wherein, the substituent on the alkyl and the alkoxy is hydroxyl, carboxyl, amino, nitro, sulfonic group or alkoxy with 1-4 carbon atoms.

4. The use of claim 1, wherein: r4 is selected from substituted alkyl with 1-12 carbon atoms or alkoxy with 1-12 carbon atoms, wherein, the substituent on the alkyl and the alkoxy is hydroxyl, halogen, cyano, carboxyl, amino, nitryl, sulfonic group or alkoxy with 1-4 carbon atoms.

5. The use of claim 1, wherein: x is selected from fluoride, chloride, bromide, iodide, sulfate, acetate or alkyl sulfate.

6. A composition for inhibiting electroless plating bleed, characterized by: comprising a palladium source, an acid, a solvent and at least one quaternary ammonium salt compound according to any one of claims 1 to 5.

7. The electroless plating-inhibited composition according to claim 6, wherein: in the composition, the concentration of the quaternary ammonium salt compound is 0.001-5 g/L, the concentration of palladium ions provided by the palladium source is 0.001-5 g/L, and the concentration of the acid is 5-200 g/L.

8. A method for preparing a metal layer by chemical plating is characterized by comprising the following steps: comprising the step of treating a product to be processed by adding the quaternary ammonium salt compound according to any one of claims 1 to 5 during activation before electroless plating.

9. The method of preparing a metal layer by electroless plating according to claim 8, wherein: comprising the step of treating a product to be processed with the composition for suppressing electroless plating bleeding according to any one of claims 6 to 7 in an activation process before electroless plating.

10. A printed circuit board or wafer, comprising: the printed circuit board or the wafer comprises a metal layer prepared by the method of any one of claims 8-9.