CN113207243A - Preparation and application method of black hole liquid - Google Patents
Preparation and application method of black hole liquid Download PDFInfo
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- CN113207243A CN113207243A CN202110499905.8A CN202110499905A CN113207243A CN 113207243 A CN113207243 A CN 113207243A CN 202110499905 A CN202110499905 A CN 202110499905A CN 113207243 A CN113207243 A CN 113207243A
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- Prior art keywords
- black hole
- black
- hole liquid
- preparing
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Classifications
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
- H05K3/42—Plated through-holes or plated via connections
- H05K3/423—Plated through-holes or plated via connections characterised by electroplating method
- H05K3/424—Plated through-holes or plated via connections characterised by electroplating method by direct electroplating
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/54—Electroplating of non-metallic surfaces
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D7/00—Electroplating characterised by the article coated
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
- H05K3/42—Plated through-holes or plated via connections
- H05K3/425—Plated through-holes or plated via connections characterised by the sequence of steps for plating the through-holes or via connections in relation to the conductive pattern
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
- H05K2201/09—Shape and layout
- H05K2201/09209—Shape and layout details of conductors
- H05K2201/095—Conductive through-holes or vias
Abstract
The invention discloses a preparation method and a use method of black hole liquid used in the printed circuit board industry, wherein the black hole liquid comprises the following components: conductive agent, graphene oxide, dispersant and binder. The method comprises the following steps: and (3) electrolyzing by taking a graphite plate as an anode, a titanium plate or a graphite plate as a cathode and ultrapure water or an ammonia water solution as electrolyte, adding a conductive agent and a binder after electrolyzing for a certain time, and adjusting the pH to 9-10 to obtain the black pore liquid. The black pore liquid prepared by the method can be used for treating the surface of the non-metallic substrate of the printed circuit board or the pore wall after pretreatment to obtain a conductive film layer with good binding force and conductivity.
Description
Technical Field
The invention relates to the field of printed circuit board manufacturing, in particular to a preparation method and a use method of black hole liquid capable of directly electroplating a printed circuit board.
Background
The connection of the lines between the double-layer board or the multi-layer board is realized after the metallization of the conductive holes between the boards, which is called hole metallization for short. There are two main techniques of hole metallization development to date: electroless copper plating techniques and direct plating techniques. The chemical plating is the earliest and the most mature as the hole metallization technology, is widely used by various manufacturers, but the chemical plating also contains carcinogenic formaldehyde and other substances along with the problem of environmental pollution, and the stability of the chemical copper plating solution needs to be strictly monitored and maintained and noble metal palladium is used in the process, so the cost is high, and the long-term development is not facilitated. Therefore, the direct electroplating technology is produced accordingly and is receiving attention. At present, there are three main types of direct plating techniques: metallic palladium series, polymer conductive film series, and black hole series. The metal palladium series has higher cost, consumes rare noble metals and has the defects of thick two ends and thin middle of the hole wall. The high molecular conductive film series realizes metal guide holes by high molecular conductive polymers, uses polypyrrole, polyaniline and the like, and has harsh reaction conditions. The black hole series adopts carbon black, graphite or graphene as a conductive material, and a conductive layer is formed on the hole wall and then is directly electroplated. The black hole series take carbon black, graphite or graphene as main raw materials, are low in cost, non-toxic and harmless, free of formaldehyde addition, environment-friendly, and suitable for the concept of green sustainable development, and have a very high application prospect. At present, black hole liquid (such as CN106535505A, CN104562115A, US5015339, US5389270, P4724005A and the like) adopted by a direct electroplating process for hole metallization of a printed circuit board is suspension liquid which takes water as a dispersion medium and carbon black/graphite particles as a conductive matrix, but the suspension liquid is unstable and easy to generate coagulation, and the service performance of the black hole liquid is seriously influenced. The existing black hole liquid is generally composed of aqueous solution of graphite, carbon black or graphene, and the existing black hole liquid has the problem that the binding force of a plating layer and the conductivity are mutually contradictory after hole metallization, namely, the improvement of the conductivity of the black hole can cause weak binding force of the plating layer, and the improvement of the binding force of the plating layer can cause weak conductivity of the black hole, so that the plating time is too long. The contradiction between the two limits the application of the black hole liquid to a certain extent.
Disclosure of Invention
The present invention is directed to solving at least the major problems in the prior art. Therefore, the first purpose of the invention is to provide a preparation method of the black hole liquid, the conductive layer formed by black hole formation of the black hole liquid prepared by the method has higher conductivity, the bonding force of the plating layer is good after direct electroplating, and the electroplating completion time is short.
The technical purpose of the invention is realized by the following technical scheme:
a preparation method of black hole liquid comprises the following steps: the preparation method comprises the steps of taking a graphite plate as an anode, a titanium plate or the graphite plate as a cathode, taking water or ammonia water as electrolyte, carrying out electrolysis, adding a conductive agent and a binder, stirring and mixing uniformly, and adjusting the pH to 9-10.
The conductive agent is graphene, the graphene is extremely low in oxidation degree, the particle size is 500 nm-5 mu m, and the number of layers is 1-20. The graphene and the graphene oxide have similar structures and delocalized large pi bonds, the graphene oxide can well wrap the graphene due to the strong pi-pi interaction between the two similar sheets, and when the graphene and the graphene oxide sheets are dried after black holes, automatic arrangement and automatic assembly in mutual lamination of the graphene and the graphene oxide sheets are realized due to evaporation of moisture.
Preferably, the graphite plate as the anode is characterized in that: ash content less than 50 ppm and volume density of 1.5-20 g/cm3The granularity is less than 500 mu m.
Preferably, the distance between the anode and the cathode is 5-10 mm.
Preferably, the concentration of the ammonia water is 0.1-3 mol/L.
Preferably, the electrolysis conditions are as follows: the voltage is 6-60V, and the current density is 10-300 mA/cm2The electrolysis time is 8-168 h.
Preferably, the mass ratio percentage of the conductive agent in the black hole liquid is 4.0-10.0%.
Preferably, the volume percentage of the dispersant in the black pore liquid is 0.12-0.16%.
Preferably, the dispersing agent is at least one or a combination of more than two of octyl phenol polyoxyethylene ether, dimethylformamide and N-methylpyrrolidone.
Preferably, the binder comprises at least one or a combination of two or more of polyacrylic acid, sodium polyacrylate, water-based acrylate, epoxy resin, water-based polyurethane or water glass.
Preferably, the mass percentage of the binder in the black pore liquid is 0.82-25%.
Preferably, the pH value of the black pore liquid is 9-10.
The second purpose of the invention is to provide a use method of the black hole liquid, which comprises the following steps: and (3) soaking the laminated printed circuit board in the black hole liquid at the temperature of 25-35 ℃, taking out the laminated printed circuit board, drying by cold air, and drying.
Preferably, the time of the impregnation is 20 to 90 s.
Preferably, the drying temperature is 40-100 ℃.
The invention has the beneficial effects that:
(1) the preparation method of the black hole liquid has the advantages of simple process, convenient operation and environmental protection. In the preparation process of the black hole liquid for the printed circuit board, the stable black hole liquid can be obtained without grinding and adding less dispersing agent.
(2) The black hole liquid has stronger stability. In the oxidation and electrolysis process of the graphite plate, graphene oxide (with the particle size of 2-5 nm) is continuously generated, and after the conductive agent graphene is added, due to the fact that the graphene oxide and the graphene are similar in structure and strong van der Waals force exists between the graphene oxide and the graphene, the graphene is wrapped by the graphene oxide, and therefore the water solubility of the graphene and the stability of the graphene in an aqueous solution are improved.
(3) In the use process of the black hole liquid, the finally formed conductive layer has higher conductivity. The black hole liquid prepared by the invention uses relatively less dispersant, so that the dispersant is less mixed in the conductive layer formed in the using process, and higher conductivity and shorter electroplating completion time can be obtained.
(4) In the use process of the black hole liquid, the binding force of a copper plating layer after the finally formed conductive layer is electroplated is good, and the stripping test of the surface of the non-metallic substrate of the printed circuit board shows that the copper plating layer is hardly stripped.
(5) In the using process of the black hole liquid, the black hole liquid is prepared within an allowable range, the fault tolerance is high, and the prepared black hole liquid can still achieve the purpose.
The specific implementation mode is as follows:
the present invention will be further described with reference to the following specific examples.
Example 1:
a preparation method of black hole liquid comprises the following steps: taking a graphite plate with the thickness of 80 mm, the length of 700 mm and the width of 700 mm as an anode, wherein the ash content is 50 ppm, and the volume density is 2.0 g/cm3The granularity is 500 mu m; a titanium plate with the thickness of 10 mm, the length of 700 mm and the width of 700 mm is taken as a cathode; the distance between the graphite plate and the titanium plate is 5 mm; the electrolyte is ultrapure water with the resistivity of more than 18 MOmega; the power supply is rectified DC power supply, and during electrolysis, the voltage is 6-60V, and the current density is 60 mA/cm2And after electrolyzing for 168 hours, stopping electrolyzing, adding 6.55 mass percent of conductive agent and 1.64 mass percent of binder, and adjusting the pH to 9-10 to obtain the black pore liquid A.
Example 2:
a preparation method of black hole liquid comprises the following steps: taking a graphite plate with the thickness of 80 mm, the length of 700 mm and the width of 700 mm as an anode, wherein the ash content of the graphite plate is 45 ppm, and the volume density of the graphite plate is 1.5 g/cm3The granularity is 450 mu m; a titanium plate with the thickness of 10 mm, the length of 700 mm and the width of 700 mm is taken as a cathode; the distance between the graphite plate and the titanium plate is 5 mm; the electrolyte is 2.5 mol/L ammonia water solution; the power supply is pulse power supply, and the current density is controlled at 250A/cm during electrolysis2And the frequency is 10k Hz, the electrolysis is stopped after 24 hours of electrolysis, a conductive agent with the mass ratio of 6.25 percent and a binding agent with the mass ratio of 6.25 percent are added, and the pH value is adjusted to 9-10 to obtain the black pore liquid B.
Example 3:
a preparation method of black hole liquid comprises the following steps: taking a graphite plate with the thickness of 80 mm, the length of 700 mm and the width of 700 mm as an anode, wherein the ash content is 40 ppm, and the volume density is 2.0 g/cm3The granularity is 380 mu m; a titanium plate with the thickness of 10 mm, the length of 700 mm and the width of 700 mm is taken as a cathode; the distance between the graphite plate and the titanium plate is 10 mm; the electrolyte is ultrapure water with the resistivity of more than 18 MOmega; the power supply is rectified DC power supply, and during electrolysis, the voltage is 6-60V, and the current density is 10-300 mA/cm2After 96 hours of electrolysis, the electrolysis was stopped and addedAdding 5.88 mass percent of conductive agent and 11.76 mass percent of binder, and adjusting the pH value to 9-10 to obtain black pore liquid C.
Example 4:
a use method of black hole liquid comprises the following steps: and (2) soaking the laminated printed circuit board in the black hole liquid A for 20s at 25 ℃ to finish primary black hole drying by cold air, soaking the laminated printed circuit board in the black hole liquid A for 10s to finish secondary black hole drying by cold air, and after the black hole treatment is finished, drying the laminated printed circuit board at 60 ℃ to form a conductive layer A on the wall of the through hole on the laminated printed circuit board, and electroplating to form a copper-plated layer A.
Example 5:
a use method of black hole liquid comprises the following steps: and (2) soaking the laminated printed circuit board in the black hole liquid B for 40s at 25 ℃ to finish primary black hole drying by cold air, soaking the laminated printed circuit board in the black hole liquid B for 10s to finish secondary black hole drying by cold air, and after the black hole treatment is finished, drying the laminated printed circuit board at 80 ℃ to form a conductive layer B on the wall of the through hole on the laminated printed circuit board, and electroplating to form a copper-plated layer B.
Example 6:
a use method of black hole liquid comprises the following steps: and (2) soaking the laminated printed circuit board in the black hole liquid C for 20s at the temperature of 25 ℃ to finish primary black hole drying by cold air, soaking the laminated printed circuit board in the black hole liquid C for 10s to finish secondary black hole drying by cold air, and after the black hole treatment is finished, drying the laminated printed circuit board at the temperature of 70 ℃ to form a conductive layer C on the wall of the through hole on the laminated printed circuit board, and electroplating to form a copper-plated layer C.
Test example:
and (3) conductivity test: the conductive layers of examples 4-6 were tested for square resistance and the results are shown in Table 1.
Table 1: conductive layer conductivity test results
As can be seen from table 1, in the using process of the black hole solution of the present invention, compared with similar products, the finally formed conductive layer has better conductivity, and the plating time in the subsequent process is within 300 s.
Judging the appearance grade of the hundred-grid cutter: the copper plating layers of examples 4 to 6 were subjected to laboratory conditions in accordance with GB/T9286-98, and the results of evaluation of the hundred-grid-cutter appearance were shown in Table 2.
Table 2: copper plated layer check knife appearance grade
As can be seen from Table 2, compared with similar products, the black hole liquid of the present invention has a good bonding force of the finally formed copper plating layer during the use process, and under the optimal condition, the finally formed copper plating layer can reach the degree that the copper plating layer is hardly stripped.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.
Claims (16)
1. A preparation method of black hole liquid is characterized by comprising the following steps: the method comprises the following steps: taking a graphite plate as an anode, a titanium plate or a graphite plate as a cathode, taking ultrapure water or an ammonia water solution as electrolyte, carrying out electrolysis, adding a conductive agent and a binder, and adjusting the pH to 9-10 to obtain the catalyst.
2. The method for preparing a black hole liquid according to claim 1, wherein: the conductive agent is graphene, the graphene is extremely low in oxidation degree, the particle size is 500 nm-5 mu m, and the number of layers is 1-20.
3. The method for preparing a black hole liquid according to claim 1, wherein: the concentration of the ammonia water solution is 0.1-3 mol/L.
4. The method for preparing a black hole liquid according to claim 1, wherein: the graphite plate as the anode is characterized in that: ash content less than or equal to 50 ppm and volume density of 1-20 g/cm3The granularity is less than 500 mu m.
5. The method for preparing a black hole liquid according to claim 1, wherein: the conditions of the electrolysis are as follows: the voltage is 6-60V, and the current density is 10-300 mA/cm2The electrolysis time is 8-168 h.
6. The method for preparing a black hole liquid according to claim 1, wherein: the mass ratio percentage of the conductive agent in the black pore liquid is 4.0-10.0%.
7. The method for preparing a black hole liquid according to claim 1, wherein: the volume percentage of the dispersant in the black pore liquid is 0.12-0.16%.
8. The method for preparing a black hole liquid according to claim 1, wherein: the dispersing agent comprises at least one or the combination of more than two of octyl phenol polyoxyethylene ether, dimethylformamide and N-methyl pyrrolidone.
9. The method for preparing a black hole liquid according to claim 1, wherein: the binder comprises at least one or the combination of more than two of polyacrylic acid, sodium polyacrylate, water-based acrylate, epoxy resin, water-based polyurethane or water glass.
10. The method for preparing a black hole liquid according to claim 1, wherein: the mass percentage of the binder in the black pore liquid is 0.82-25%.
11. The method for preparing a black hole liquid according to claim 1, wherein: the pH value of the black pore liquid is 9-10.
12. The method for preparing a black hole liquid according to claim 1, wherein: the method comprises the following steps: and uniformly mixing the conductive agent, the graphene oxide, the dispersing agent, the binder and water according to the mass ratio percentage and the volume ratio percentage to obtain the black pore liquid.
13. A black hole liquid is characterized in that: prepared by the preparation method of any one of claims 1 to 12.
14. The use method of the black hole liquid is characterized by comprising the following steps: dipping the laminated printed circuit board in the black hole liquid of claim 13 at 25-35 ℃, taking out the laminated printed circuit board, drying by cold air, and drying.
15. The method of using a black hole fluid as claimed in claim 14, wherein: the immersion time is 20-90 s.
16. The method of using a black hole fluid as claimed in claim 14, wherein: the drying temperature is 40-100 ℃.
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| CN202110499905.8A CN113207243A (en) | 2021-05-08 | 2021-05-08 | Preparation and application method of black hole liquid |
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| CN202110499905.8A CN113207243A (en) | 2021-05-08 | 2021-05-08 | Preparation and application method of black hole liquid |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115594171A (en) * | 2022-07-29 | 2023-01-13 | 广东利尔化学有限公司（Cn） | Carbon pore process nano graphite dispersion liquid and preparation method thereof |
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| CN103491727A (en) * | 2013-09-29 | 2014-01-01 | 哈尔滨工业大学 | Method using printed circuit board graphite oxide reduction method to carry out hole conductivity |
| CN108323036A (en) * | 2018-02-10 | 2018-07-24 | 深圳市祥盛兴科技有限公司 | A kind of blank hole liquid and black holes chemical industry skill |
| CN108834309A (en) * | 2018-08-30 | 2018-11-16 | 陈伟元 | A kind of graphene metallization solution and the preparation method and application thereof |
| CN109811382A (en) * | 2019-03-28 | 2019-05-28 | 烟台恒诺新材料有限公司 | A kind of application of graphene oxide conductive paste in black holesization is directly electroplated |
| CN111647901A (en) * | 2020-05-15 | 2020-09-11 | 湖北省哈福生物化学有限公司 | Black hole liquid and preparation method and use method thereof |
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2021
- 2021-05-08 CN CN202110499905.8A patent/CN113207243A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103491727A (en) * | 2013-09-29 | 2014-01-01 | 哈尔滨工业大学 | Method using printed circuit board graphite oxide reduction method to carry out hole conductivity |
| CN108323036A (en) * | 2018-02-10 | 2018-07-24 | 深圳市祥盛兴科技有限公司 | A kind of blank hole liquid and black holes chemical industry skill |
| CN108834309A (en) * | 2018-08-30 | 2018-11-16 | 陈伟元 | A kind of graphene metallization solution and the preparation method and application thereof |
| CN109811382A (en) * | 2019-03-28 | 2019-05-28 | 烟台恒诺新材料有限公司 | A kind of application of graphene oxide conductive paste in black holesization is directly electroplated |
| CN111647901A (en) * | 2020-05-15 | 2020-09-11 | 湖北省哈福生物化学有限公司 | Black hole liquid and preparation method and use method thereof |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115594171A (en) * | 2022-07-29 | 2023-01-13 | 广东利尔化学有限公司（Cn） | Carbon pore process nano graphite dispersion liquid and preparation method thereof |
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