CN115261833A - Chemical silver plating solution for printed circuit board, preparation method and chemical silver plating method - Google Patents
Chemical silver plating solution for printed circuit board, preparation method and chemical silver plating method Download PDFInfo
- Publication number
- CN115261833A CN115261833A CN202210939957.7A CN202210939957A CN115261833A CN 115261833 A CN115261833 A CN 115261833A CN 202210939957 A CN202210939957 A CN 202210939957A CN 115261833 A CN115261833 A CN 115261833A
- Authority
- CN
- China
- Prior art keywords
- plating solution
- silver plating
- circuit board
- printed circuit
- silver
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
- C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
- C23C18/31—Coating with metals
- C23C18/42—Coating with noble metals
Landscapes
- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemically Coating (AREA)
Abstract
The invention discloses a chemical silver plating solution for a printed circuit board, which comprises soluble silver ions, carboxyl imidazolium salt ionic liquid and deionized water, wherein the concentration of the soluble silver ions is 0.1-15g/L; the volume percentage of the carboxyl imidazolium salt ionic liquid mixed with deionized water is 1-100%, and the pH value of the chemical silver plating solution of the printed circuit board is 0-6. The carboxyl imidazolium salt ionic liquid has double functions of chelating and refining crystal grains, has a certain inhibiting effect on copper ions, can form a stable complex with silver ions, and can form a uniform and bright replacement silver coating on a copper wire on a printed circuit board. The chemical silver plating solution for the printed circuit board has the advantages of simple components, high stability of the plating solution, small biting corrosion on a copper matrix, low galvanic effect, excellent bonding performance of the formed silver plating layer and the copper matrix, low organic matter content and simple wastewater treatment, and effectively meets the requirements of high fineness and green environmental development of the circuit board industry.
Description
Technical Field
The invention relates to the technical field of surface treatment of printed circuit boards, in particular to a chemical silver plating solution for a printed circuit board.
Background
After the surface of the printed circuit board is treated, the oxidation of the copper surface can be delayed, and the product quality and reliability of the circuit board in the packaging process can be improved. At present, the surface treatment process of the printed circuit board mainly comprises HASL (hot air leveling), chemical nickel/gold plating, OSP (organic solder resist), chemical tin plating and chemical silver plating. However, the HASL has a turtleback phenomenon and is lack of smoothness; the chemical nickel/gold plating process is complex and the cost is expensive; the OSP is fragile in thin layer, and the thickness of the film is not easy to control; the chemical nickel plating has the problem of long-term effect due to tin whisker. The chemical silver plating has lower cost, smooth plating layer, good compactness and less environmental pollution, and better meets the requirements of high fineness and green environmental development of the circuit board industry. However, electroless silver plating suffers from problems such as peeling of the silver layer, corrosion of the copper substrate, and discoloration of the plating layer.
Accordingly, the prior art is deficient and needs improvement.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the chemical silver plating solution, the preparation method and the chemical silver plating method for the printed circuit board aim to solve the problems of stability of plating solution and reliability of plating layer of chemical silver plating in the production process of the printed circuit board.
The technical scheme of the invention is as follows: a chemical silver plating solution for a printed circuit board comprises soluble silver ions, carboxyl imidazole salt ionic liquid and deionized water, wherein the concentration of the soluble silver ions is 0.1g/L-15g/L; after the carboxyl imidazolium salt ionic liquid is mixed with deionized water, the volume percentage of the carboxyl imidazolium salt ionic liquid is 1-100%, and the pH value of the chemical silver plating solution of the printed circuit board is 0-6.
The chemical silver plating solution for the printed circuit board is applied to the technical scheme, the soluble silver ions are introduced in the form of silver compounds, and the silver compounds are one or more of silver oxide, silver nitrate, silver methylsulfonate and silver acetate.
The chemical silver plating solution for the printed circuit board has the structural general formula of carboxyl imidazolium salt ionic liquid
In the general structural formula X — Is BF 4 — 、PF 6 — 、CH 3 COO — 、CF 3 COO — 、CF 3 SO 3 — 、CH 3 SO 3 — 、NO 3 — Any one of the above; r 1 Is composed of
Wherein x and y are natural numbers, x = 1-8, x + y<10；R 2 Is straight-chain alkyl with 1 to 10 carbon atoms.
In the chemical silver plating solution for the printed wiring board, R1 and R2 in the structural general formula are respectively single carboxyl with a structure of-CnH 2n +1COOH or single carboxyl with a structure of-CnH 2n +1COOH
A dicarboxyl group of structure; wherein n, x and y are natural numbers, n = 1-10, x = 1-8, x + y<10。
The chemical silver plating solution for the printed circuit board is applied to the technical schemes, and is characterized in that: the solution also comprises a pH regulator for regulating the pH value of the chemical silver plating solution of the printed circuit board to 0-6.
The chemical silver plating solution for the printed circuit board is applied to the technical schemes, and is characterized in that: the PH regulator is one or more of formic acid, acetic acid, salicylic acid, citric acid, ammonia water, phosphoric acid, methanesulfonic acid and trifluoromethanesulfonic acid.
The preparation method of the chemical silver plating solution for the printed circuit board, which is applied to the technical schemes, comprises the following steps: step S1: mixing carboxyl imidazolium salt ionic liquid and deionized water to form a mixed solution, wherein the carboxyl imidazolium salt ionic liquid accounts for 1-100% of the volume percentage; s2, adding a soluble silver compound into the mixed solution in the step 1, and enabling the concentration of soluble silver ions to be 0.1g/L-15g/L; and S3, adding a pH regulator to enable the pH value of the chemical silver plating solution of the printed circuit board to be 0-6.
The chemical silver plating method for the printed circuit board by using the chemical silver plating solution for the printed circuit board comprises the following steps: step S1: carrying out conventional acid oil removal → DI water washing → micro etching → DI water washing → presoaking process flow treatment on the copper-clad plate through a printed circuit board; step S2: and (3) soaking the copper-clad plate processed in the step (S1) in the chemical silver plating solution for the printed circuit board at the temperature of 30 ℃, washing with water after 1min, and drying.
The invention has the beneficial effects that: the carboxyl imidazolium salt ionic liquid has a certain inhibiting effect on the influence of copper ions in the replacement reaction process, so that the stability of the solution is enhanced; and the carboxyl imidazolium salt ionic liquid and silver ions generate stable complex, and a silver coating with excellent performance can be obtained without other additives. The chemical silver plating solution provided by the invention has small corrosion on a copper matrix, has a low galvanic effect, and effectively ensures the weldability of the printed circuit board.
Detailed Description
The present invention will be described in detail with reference to the following specific examples.
Example 1
1L of chemical silver plating solution for the printed circuit board is prepared by using 1-succinic acid-3-ethylimidazole hexafluorophosphate ionic liquid.
Wherein in the structural general formula of the 1-succinic acid-3-ethylimidazole hexafluorophosphate ionic liquid, R is 1 Is composed of
R 2 is-CH 2 CH 3 ，X — Is PF 6 — 。
Taking 700ml of the 1-succinic acid-3-ethylimidazole hexafluorophosphate ionic liquid and 300ml of deionized water, and stirring and mixing 700ml of the 1-succinic acid-3-ethylimidazole hexafluorophosphate ionic liquid and 300ml of deionized water; then adding silver nitrate solution to make the concentration of silver ions be 1g/L; and finally, adding nitric acid to adjust the pH value, so that the pH value of the chemical silver plating solution for the printed circuit board is 1.
Before the chemical silver plating solution for the printed circuit board is used, the copper-clad plate needs to be subjected to the conventional acid degreasing of the printed circuit board → DI water washing → micro etching → DI water washing → presoaking process flow. And soaking the pretreated copper-clad plate in a preparation solution of a chemical silver plating solution of a printed circuit board at the temperature of 30 ℃, washing after 1min, and drying. And finally, detecting the color of the silver replacement layer, measuring the microetching thicknesses of the silver replacement layer and the copper layer, and performing 3 times of reflow soldering tests, wherein the experimental results are shown in table 1.
Example 2
1L of chemical silver plating solution for the printed circuit board is prepared by using 1, 3-propionic acid imidazole tetrafluoroborate ionic liquid.
Wherein in the structural general formula of the 1, 3-propionic acid imidazole tetrafluoroborate ionic liquid, R is 1 、R 2 Is composed of
X — Is BF 4 — 。
Taking 600ml of the 1, 3-propionic acid imidazole tetrafluoroborate ionic liquid and 400ml of deionized water, stirring and mixing 600ml of the 1, 3-propionic acid imidazole tetrafluoroborate ionic liquid and 400ml of deionized water, and then adding a silver nitrate solution to ensure that the silver ion concentration is 2g/L. Finally, citric acid was added to bring the solution to a pH of 2.
Before the chemical silver plating solution for the printed circuit board is used, the copper-clad plate needs to be subjected to the conventional acid degreasing of the printed circuit board → DI water washing → microetching → DI water washing → preimpregnation process flow. And immersing the pretreated copper-clad plate in a preparation solution of a chemical silver plating solution of a printed circuit board at the temperature of 30 ℃, washing after 1min, and drying. And finally, detecting the color of the silver replacement layer, measuring the microetching thicknesses of the silver replacement layer and the copper layer, and performing 3 times of reflow soldering tests, wherein the experimental results are shown in table 1.
Example 3
1L of chemical silver plating solution for the printed circuit board is prepared by 1, 3-imidazole propionate acetate ionic liquid. Wherein in the general structural formula of the 1, 3-imidazole propionate ionic liquid, R1 and R2 are
X — Is CH3COO — 。
Taking 800ml of the 1, 3-propionic acid imidazole acetate ionic liquid and 200ml of deionized water, stirring and mixing 800ml of the 1, 3-propionic acid imidazole acetate ionic liquid and 200ml of deionized water, and then adding a silver nitrate solution to ensure that the concentration of silver ions is 2g/L. Finally, citric acid was added to bring the solution to pH 2.
Before the chemical silver plating solution for the printed circuit board is used, the copper-clad plate needs to be subjected to the conventional acid degreasing of the printed circuit board → DI water washing → microetching → DI water washing → preimpregnation process flow. And immersing the pretreated copper-clad plate in a preparation solution of a chemical silver plating solution of a printed circuit board at the temperature of 30 ℃, washing after 1min, and drying. And finally, detecting the color of the silver replacement layer, measuring the microetching thicknesses of the silver replacement layer and the copper layer, and performing 3 times of reflow soldering tests, wherein the experimental results are shown in table 1.
Table 1: experimental results for silver layer displacement
| Color of the plating layer | Thickness of silver coating (mum) | Copper surface microetching amount (%) | Reflow test results | |
| Example 1 | Silvery white | 0.2 | 8％ | Full tin coating and good weldability |
| Example 2 | Silvery white | 0.3 | 12％ | Full tin coating and good weldability |
| Example 3 | Silvery white | 0.36 | 15％ | Full tin coating and good weldability |
Therefore, in the chemical silver plating solution for the printed circuit board, the carboxyl imidazolium salt ionic liquid has double functions of chelating and refining crystal grains, the carboxyl imidazolium salt ionic liquid has a certain inhibiting effect on copper ions, the carboxyl imidazolium salt ionic liquid can form a stable complex with silver ions, and a uniform and bright replacement silver plating layer can be formed on the copper wires on the printed circuit board. The chemical silver plating solution for the printed circuit board has the advantages of simple components, high stability of the plating solution, small corrosion to a copper matrix, low galvanic effect, excellent combination property of the formed silver plating layer and the copper matrix, low organic matter content, simple wastewater treatment and capability of effectively meeting the requirements of high fineness and green environmental development of the circuit board industry.
The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (8)
1. The chemical silver plating solution for the printed circuit board is characterized by comprising soluble silver ions, carboxyl imidazole salt ionic liquid and deionized water, wherein the concentration of the soluble silver ions is 0.1-15g/L; after the carboxyl imidazolium salt ionic liquid is mixed with deionized water, the volume percentage of the carboxyl imidazolium salt ionic liquid is 1-100%, and the pH value of the chemical silver plating solution of the printed circuit board is 0-6.
2. The electroless silver plating solution for printed wiring boards according to claim 1, wherein the soluble silver ions are introduced in the form of a silver compound from one or more of silver oxide, silver nitrate, silver methanesulfonate, silver acetate.
3. The chemical silver plating solution for the printed wiring board according to claim 1, wherein the carboxyl imidazolium salt ionic liquid has a structural general formula
In the general structural formula X — Is BF 4 — 、PF 6 — 、CH 3 COO — 、CF 3 COO — 、CF 3 SO 3 — 、CH 3 SO 3 — 、NO 3 — Any one of the above; r 1 Is composed of
Wherein x and y are natural numbers, x = 1-8, x + y<10；R 2 Is straight-chain alkyl with 1 to 10 carbon atoms.
4. The electroless silver plating solution for the printed wiring board as claimed in claim 3, wherein R1 and R2 in the general structural formula are respectively a single carboxyl group with a structure of-CnH 2n +1COOH or a single carboxyl group with a structure of-CnH 2n +1COOH
A dicarboxyl group of structure; wherein n, x and y are natural numbers, n = 1-10, x = 1-8, x + y<10。
5. The electroless silver plating solution for printed wiring boards according to claim 1, characterized in that: the solution also comprises a pH regulator for regulating the pH value of the chemical silver plating solution for the printed circuit board to 0-6.
6. The electroless silver plating solution for printed wiring boards according to claim 5, characterized in that: the PH regulator is one or more of formic acid, acetic acid, salicylic acid, citric acid, ammonia water, phosphoric acid, methanesulfonic acid and trifluoromethanesulfonic acid.
7. A process for preparing an electroless silver plating solution for printed wiring boards according to any one of claims 1 to 6, comprising the steps of:
step S1: mixing carboxyl imidazolium salt ionic liquid and deionized water to form a mixed solution, wherein the carboxyl imidazolium salt ionic liquid accounts for 1-100% of the volume percentage;
s2, adding a soluble silver compound into the mixed solution in the step 1, and enabling the concentration of soluble silver ions to be 0.1g/L-15g/L;
and S3, adding a pH regulator to enable the pH value of the chemical silver plating solution of the printed circuit board to be 0-6.
8. An electroless silver plating method for printed wiring boards using the electroless silver plating solution for printed wiring boards according to any one of claims 1 to 6, comprising the steps of:
step S1: processing the copper-clad plate by the conventional acid degreasing of a printed circuit board → DI water washing → microetching → DI water washing → presoaking process flow;
step S2: and (3) soaking the copper-clad plate processed in the step (S1) in the chemical silver plating solution for the printed circuit board at the temperature of 30 ℃, washing with water after 1min, and drying.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210939957.7A CN115261833A (en) | 2022-08-05 | 2022-08-05 | Chemical silver plating solution for printed circuit board, preparation method and chemical silver plating method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210939957.7A CN115261833A (en) | 2022-08-05 | 2022-08-05 | Chemical silver plating solution for printed circuit board, preparation method and chemical silver plating method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115261833A true CN115261833A (en) | 2022-11-01 |
Family
ID=83748418
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210939957.7A Pending CN115261833A (en) | 2022-08-05 | 2022-08-05 | Chemical silver plating solution for printed circuit board, preparation method and chemical silver plating method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115261833A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102605360A (en) * | 2011-10-12 | 2012-07-25 | 常州大学 | Chemical silvering solution based on imidazolium ionic liquid and silvering method |
| WO2017161619A1 (en) * | 2016-03-24 | 2017-09-28 | 陈铭 | Method for separating polypeptide from imidazolium ionic liquid |
| US20200362179A1 (en) * | 2019-05-15 | 2020-11-19 | The Hong Kong University Of Science And Technology | Ionic liquid-based coating and method of making articles coated with the same |
-
2022
- 2022-08-05 CN CN202210939957.7A patent/CN115261833A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102605360A (en) * | 2011-10-12 | 2012-07-25 | 常州大学 | Chemical silvering solution based on imidazolium ionic liquid and silvering method |
| WO2017161619A1 (en) * | 2016-03-24 | 2017-09-28 | 陈铭 | Method for separating polypeptide from imidazolium ionic liquid |
| US20200362179A1 (en) * | 2019-05-15 | 2020-11-19 | The Hong Kong University Of Science And Technology | Ionic liquid-based coating and method of making articles coated with the same |
Non-Patent Citations (1)
| Title |
|---|
| 耿卫国;李雪辉;王乐夫;段红丽;潘微平;: "多羧基咪唑离子液体的酸性表征", 物理化学学报, no. 02, pages 230 - 233 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101852658B1 (en) | Electroless palladium plating bath composition | |
| CN101033550B (en) | Micro-corrosion liquid and application thereof in printing wiring board silver aggradation pretreatment | |
| TWI457462B (en) | Electroless gold plating bath, electroless gold plating method and electronic parts | |
| JP2004510885A (en) | Baths and methods for electroless plating of silver on metal surfaces | |
| CN104561951A (en) | Method and plating solution for chemical plating of nickel phosphorus alloy, and nickel phosphorus alloy layer | |
| SG175937A1 (en) | Electroless palladium plating solution | |
| CN109207971B (en) | Chemical rapid reduction gold plating solution and application thereof | |
| CN104109848A (en) | Environmentally-friendly chemical gilding liquid | |
| CN108823554A (en) | A kind of chemical palladium plating solution, preparation method and its application method and application | |
| CN109536965B (en) | Tin stripping agent for removing poor tin coating of semiconductor packaging part and preparation method thereof | |
| CN109023321B (en) | Organic chemical silver plating liquid medicine | |
| CN113005437B (en) | Chemical gold-precipitating liquid for printed circuit board | |
| KR101616731B1 (en) | Metal surface treatment aqueous solution and method for inhibiting whiskers on a metal surface | |
| CN114833491B (en) | Copper surface selective organic soldering flux and use method thereof | |
| CN110318047B (en) | Chemical palladium solution applied to chemical gold-palladium-gold plating layer on PCB | |
| CN102605360B (en) | Chemical silvering solution based on imidazolium ionic liquid and silvering method | |
| KR20000053621A (en) | Electroless gold plating solution and process | |
| CN109415812B (en) | Chemical platinizing liquid | |
| CN115261833A (en) | Chemical silver plating solution for printed circuit board, preparation method and chemical silver plating method | |
| CN108823555B (en) | Reduced chemical gold plating solution and preparation method, use method and application thereof | |
| CN104498918A (en) | Chemical palladium plating solution for intermediate layer of chemical nickel, palladium and gold plating process | |
| CN109457239B (en) | Reduction type non-cyanide gold plating solution, gold plating method and gold plated product | |
| JP2013108170A (en) | Electroless palladium plating solution | |
| CN108517516B (en) | Chemical silver plating solution and preparation method thereof | |
| CN114574840A (en) | Tinning plating solution for copper electronic material, and preparation method and application method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |