CN110643985A - Chemical palladium plating process for chemical nickel-palladium-gold plating production line of printed circuit board - Google Patents
Chemical palladium plating process for chemical nickel-palladium-gold plating production line of printed circuit board Download PDFInfo
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- CN110643985A CN110643985A CN201910786619.2A CN201910786619A CN110643985A CN 110643985 A CN110643985 A CN 110643985A CN 201910786619 A CN201910786619 A CN 201910786619A CN 110643985 A CN110643985 A CN 110643985A
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- chemical
- palladium
- plating
- circuit board
- printed circuit
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- 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
- C23C18/44—Coating with noble metals using reducing agents
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- 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
- C23C18/1601—Process or apparatus
- C23C18/1633—Process of electroless plating
- C23C18/1646—Characteristics of the product obtained
- C23C18/165—Multilayered product
- C23C18/1651—Two or more layers only obtained by electroless plating
-
- 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
- C23C18/32—Coating with nickel, cobalt or mixtures thereof with phosphorus or boron
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- 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)
- Manufacturing Of Printed Wiring (AREA)
- Chemically Coating (AREA)
Abstract
The invention provides a chemical palladium plating process for a chemical nickel-palladium-gold plating production line of a printed circuit board, which comprises the steps of cleaning a chemical palladium plating tank of the chemical nickel-palladium-gold plating production line; continuously using deionized water for circular cleaning, and draining the cleaning water; adding a chemical palladium plating solution into the chemical palladium plating tank; adjusting the temperature, starting the circulating filter pump, and simultaneously opening an air stirring valve to stir air; washing the printed circuit board after chemical nickel plating, putting the washed printed circuit board into a chemical palladium plating tank for chemical palladium plating, taking out the printed circuit board after chemical palladium plating, putting the washed printed circuit board into a chemical gold plating tank for conventional chemical gold plating, taking out the printed circuit board after chemical gold plating, washing the printed circuit board with water, and drying the printed circuit board by hot air; and (5) turning to a shape processing procedure. The process of the invention improves the corrosion resistance of the chemical nickel-palladium-gold plating, and enables the gold surface to keep excellent welding performance for a long time, thereby improving the product quality and the product reliability, having no pollution in the production process and being suitable for industrial production.
Description
Technical Field
The invention belongs to the technical field of printed circuit board processing, and particularly relates to a chemical palladium plating process for a printed circuit board chemical nickel-palladium-gold plating production line.
Background
Along with the high, integrated height of printed wiring board, intensive continuous improvement, also higher and higher to the welding requirement and the reliability of welding in the surface packaging of components and parts, printed wiring board adopts chemical nickel gold plating at present mostly. The welding performance of surface packaging of components is improved, but the chemical nickel-plating gold has the following serious defects: 1) at present, chemical nickel plating and gold plating are mostly carried out by adopting a chemical displacement reaction method, and in view of the fact that the atomic size difference of nickel and gold is large, a large gap exists between the interfaces of gold layer atomic crystals on displacement, and chemical liquid medicine or water vapor is easy to remain, so that a chemical nickel plating layer is easy to corrode, the welding performance or the welding reliability is seriously affected, and the hidden quality trouble caused by nickel corrosion becomes the main quality defect of chemical nickel plating and gold plating. 2) At present, in order to solve the problems, electroless nickel gold plating also adopts a non-substituted reducing agent to participate in electroless gold plating. However, this process is expensive, uneconomical and difficult to be popularized.
Therefore, a new process for solving the problem of nickel corrosion of electroless nickel-gold plating to solve the problem of solderability and soldering reliability in surface packaging of components is urgently needed.
Disclosure of Invention
In view of the above problems, an object of the present invention is to provide a chemical palladium plating process for a chemical nickel-palladium-gold plating production line of a printed circuit board, so as to replace the existing chemical nickel-gold plating process, thereby improving the soldering quality and the soldering reliability of the printed circuit board.
The invention provides a chemical palladium plating process for a chemical nickel, palladium and gold plating production line of a printed circuit board, which comprises the following steps: 1) cleaning a chemical palladium plating tank of a chemical nickel-palladium-gold plating production line; 2) Continuously using deionized water for circular cleaning, and draining the cleaning water; 3) adding a chemical palladium plating solution into a chemical palladium plating tank, wherein the chemical palladium plating solution comprises deionized water, palladium chloride, triethanolamine, ethylene diamine tetraacetic acid disodium salt, ammonia water, thiourea and sodium hypophosphite; 4) adjusting the temperature to 45-55 ℃, starting a circulating filter pump, and simultaneously opening an air stirring valve for air stirring; 5) washing the printed circuit board subjected to chemical nickel plating with water, and then placing the printed circuit board into the chemical palladium plating tank in the step 3); 6) chemical palladium plating is carried out for 5-10 minutes; 7) taking out the printed circuit board subjected to chemical palladium plating, washing with water, and placing the printed circuit board into a chemical gold plating tank for chemical gold plating; 8) taking out the printed circuit board chemically plated with gold in the step 7, then washing with water, and drying by adopting hot air at 70-85 ℃; 9) and (5) turning to a shape processing procedure. Wherein, the electroless gold plating in the step 7) is a conventional electroless gold plating method.
As a further explanation of the electroless palladium plating process according to the present invention, preferably, the electroless palladium plating solution includes: deionized water, 0.1-0.5 wt% of palladium chloride, 2.0-10.0 wt% of triethanolamine, 1.0-5.0 wt% of disodium ethylenediamine tetraacetic acid, 10-20 wt% of ammonia water, 15-35ppm of thiourea and 0.3-2.0 wt% of sodium hypophosphite.
As a further explanation of the electroless palladium plating process of the invention, preferably, the electroless palladium plating solution has a pH value of 6-10 and a specific gravity of 1.08-1.16g/cm3。
As a further description of the electroless palladium plating process according to the present invention, in step 2), the time for rinsing with deionized water is preferably 30 minutes.
As a further description of the electroless palladium plating process of the present invention, preferably, in step 7), the time of washing after electroless palladium plating is 1-2min, and the temperature is room temperature.
As a further description of the electroless palladium plating process of the present invention, preferably, in step 8), the electroless gold plating is followed by washing with water for 1-2min at 50-60 ℃ and drying with hot air at 85 ℃ for 3-4 min.
The chemical palladium plating process has the following beneficial effects: (1) due to the introduction of the chemical plating palladium, the potential of the metal palladium is far higher than that of the metal nickel (VPd pd)2+(pd +0.82 v), VNi Ni2+the/Ni is-0.25 v), therefore, after the gold is replaced on the palladium, the corrosion resistance is greatly improved because the bottom layer is the palladium instead of the nickel; (2) after chemical palladium plating is adopted, expensive non-displacement gold plating is not needed, so that the manufacturing cost is saved; (3) the nickel corrosion, the welding performance and the welding reliability are greatly improved, and the product quality and the product reliability are improved; (4) the raw materials have wide sources, low price, low cost and no pollution in the production process, thereby having wide application prospect in the field of surface treatment of printed circuit boards.
The chemical palladium plating process of the printed circuit board chemical nickel-palladium-gold plating production line mainly solves the problem of nickel corrosion of the conventional chemical nickel-gold plating, and avoids poor weldability of the chemical nickel-gold plating, poor weather-resistant conditions and incapability of meeting the requirements of high weldability on product quality and reliability due to nickel corrosion. The chemical palladium plating process of the printed circuit board chemical nickel palladium gold production line can greatly improve the corrosion resistance of the chemical palladium gold plating, lead the gold surface to keep excellent welding performance for a long time, and eliminate the defects of insufficient soldering, missing soldering, poor welding reliability and the like, thereby improving the product quality and the product reliability, having no pollution in the production process and being suitable for industrial production.
Detailed Description
In order to further understand the structure, characteristics and other objects of the present invention, the following detailed description is given with reference to the preferred embodiments, which are only used for illustrating the technical solutions of the present invention and are not to limit the present invention.
Example 1
Preparing a chemical palladium plating process solution: 2.0 wt% triethanolamine, 1.0 wt% disodium ethylenediaminetetraacetate, 0.1 wt% palladium chloride, 10.0 wt% ammonia, 15ppm thiourea, 0.3 wt% sodium hypophosphite; and (4) adopting deionized water for preparation. The system in the chemical palladium plating process is as follows: pH value: 6-10, specific gravity: 1.08-1.16g/cm3。
The invention plates the palladium on the prepared chemical palladium plating process solution according to the following process steps, which specifically comprise the following steps: 1) cleaning a chemical palladium plating tank of a chemical nickel-palladium-gold plating production line; 2) Continuously using deionized water for circular cleaning, and draining the cleaning water; 3) adding the prepared chemical palladium plating process solution into a chemical palladium plating tank; 4) adjusting the temperature to 45 ℃; 5) starting a circulating filter pump, and stirring with air; 6) washing a printed circuit board subjected to conventional chemical nickel plating with water, and putting the printed circuit board into a chemical palladium plating tank added with the chemical palladium plating process solution; 7) chemical palladium plating is carried out for 10 minutes; 8) Taking out the chemical palladium plating printed circuit board, washing with water, and then putting the circuit board into a chemical gold plating tank for conventional chemical gold plating; 9) taking out the chemical gold-plated printed circuit board, washing with water, and drying with hot air at 85 ℃; 10) and (5) turning to a shape processing procedure.
The chemical palladium plating printed circuit board obtained according to the steps has excellent salt spray resistance, excellent weldability and welding reliability, and the corrosion condition of the welding surface is not found, so that the quality of surface treatment of the printed circuit board and the reliability of the product are greatly improved. Referring to table 1, table 1 lists the relevant parameters after electroless palladium plating.
TABLE 1
As can be seen from the experimental results of Table 1, the electroless palladium plating printed wiring board of the present invention greatly improves the quality of the surface treatment of the printed wiring board and the reliability of the product.
Example 2
Preparing a chemical palladium plating process solution: 10.0 wt% triethanolamine, 5.0 wt% disodium ethylenediaminetetraacetate, 0.5 wt% palladium chloride, 20 wt% ammonia water, 35ppm thiourea, 2.0 wt% sodium hypophosphite. And (4) adopting deionized water for preparation. The system in the chemical palladium plating process is as follows: pH value: 6-10, specific gravity: 1.08-1.16g/cm3。
The invention plates the palladium on the prepared chemical palladium plating process solution according to the following process steps, which specifically comprise the following steps: 1) cleaning a chemical palladium plating tank of a chemical nickel-palladium-gold plating production line; 2) Continuously using deionized water for circular cleaning, and draining the cleaning water; 3) adding the prepared chemical palladium plating process solution into a chemical palladium plating tank; 4) adjusting the temperature to 55 ℃; 5) starting a circulating filter pump, and stirring with air; 6) washing a printed circuit board subjected to conventional chemical nickel plating with water, and putting the printed circuit board into a chemical palladium plating tank added with the chemical palladium plating process solution; 7) chemical palladium plating is carried out for 5 minutes; 8) Taking out the chemical palladium plating printed circuit board, washing with water, and then putting the circuit board into a chemical gold plating tank for conventional chemical gold plating; 9) taking out the chemical gold-plated printed circuit board, washing with water, and drying with hot air at 85 ℃; 10) and (5) turning to a shape processing procedure.
The chemical palladium plating printed circuit board obtained according to the steps has excellent salt spray resistance, excellent weldability and welding reliability, and the corrosion condition of the welding surface is not found, so that the quality of surface treatment of the printed circuit board and the reliability of the product are greatly improved. Referring to table 2, table 2 lists the relevant parameters after electroless palladium plating.
TABLE 2
As can be seen from the experimental results of Table 2, the electroless palladium plating printed wiring board of the present invention greatly improves the quality of the surface treatment of the printed wiring board and the reliability of the product.
Therefore, the chemical palladium plating process for chemically plating nickel, palladium and gold on the printed circuit board mainly solves the problem of nickel corrosion of the conventional chemical nickel and gold plating, avoids poor weldability of the chemical nickel and gold plating caused by nickel corrosion, has poor weather-proof conditions, and cannot meet the requirement of high weldability on the quality and reliability of products. The chemical palladium plating process of chemical nickel-palladium-gold can greatly improve the corrosion resistance of the chemical palladium-gold plating, lead the gold surface to keep excellent welding performance for a long time, and eliminate the defects of insufficient solder, missing solder, poor welding reliability and the like, thereby improving the product quality and the product reliability, having no pollution in the production process and being suitable for industrial production.
It should be noted that the above summary and the detailed description are intended to demonstrate the practical application of the technical solutions provided by the present invention, and should not be construed as limiting the scope of the present invention. Various modifications, equivalent substitutions, or improvements may be made by those skilled in the art within the spirit and scope of the present invention. The scope of the invention is to be determined by the appended claims.
Claims (6)
1. A chemical palladium plating process for a chemical nickel, palladium and gold plating production line of a printed circuit board is characterized by comprising the following steps:
1) cleaning a chemical palladium plating tank of a chemical nickel-palladium-gold plating production line;
2) continuously using deionized water for circular cleaning, and draining the cleaning water;
3) adding a chemical palladium plating solution into a chemical palladium plating tank, wherein the chemical palladium plating solution comprises deionized water, palladium chloride, triethanolamine, ethylene diamine tetraacetic acid disodium salt, ammonia water, thiourea and sodium hypophosphite;
4) adjusting the temperature to 45-55 ℃, starting a circulating filter pump, and simultaneously opening an air stirring valve for air stirring;
5) washing the printed circuit board subjected to chemical nickel plating with water, and then placing the printed circuit board into the chemical palladium plating tank in the step 3);
6) chemical palladium plating is carried out for 5-10 minutes;
7) taking out the printed circuit board subjected to chemical palladium plating, washing with water, and placing the printed circuit board into a chemical gold plating tank for chemical gold plating;
8) taking out the printed circuit board chemically plated with gold in the step 7, then washing with water, and drying by adopting hot air at 70-85 ℃;
9) and (5) turning to a shape processing procedure.
2. The electroless palladium plating process according to claim 1, wherein the electroless palladium plating solution comprises: 0.1-0.5 wt% of palladium chloride, 2.0-10.0 wt% of triethanolamine, 1.0-5.0 wt% of disodium ethylenediamine tetraacetic acid, 10-20 wt% of ammonia water, 15-35ppm of thiourea and 0.3-2.0 wt% of sodium hypophosphite.
3. The electroless palladium plating process according to claim 2, wherein the electroless palladium plating solution has a pH value of 6 to 10 and a specific gravity of 1.08 to 1.16g/cm3。
4. The electroless palladium plating process according to claim 1, wherein in the step 2), the deionized water washing time is 30 minutes.
5. The electroless palladium plating process according to claim 1, wherein in the step 7), the time of washing after electroless palladium plating is 1-2min, and the temperature is room temperature.
6. The electroless palladium plating process according to claim 1, wherein in the step 8), the electroless gold plating is carried out for 1-2min, the temperature is 50-60 ℃, and the electroless gold plating is carried out by hot air blowing at 85 ℃ for 3-4 min.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910786619.2A CN110643985A (en) | 2019-08-24 | 2019-08-24 | Chemical palladium plating process for chemical nickel-palladium-gold plating production line of printed circuit board |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201910786619.2A CN110643985A (en) | 2019-08-24 | 2019-08-24 | Chemical palladium plating process for chemical nickel-palladium-gold plating production line of printed circuit board |
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| CN110643985A true CN110643985A (en) | 2020-01-03 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111763932A (en) * | 2020-06-01 | 2020-10-13 | 东莞市斯坦得电子材料有限公司 | Nickel plating process for flexible printed circuit board |
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2019
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN111763932A (en) * | 2020-06-01 | 2020-10-13 | 东莞市斯坦得电子材料有限公司 | Nickel plating process for flexible printed circuit board |
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