Pulse copper plating production method with recovery processing function

Abstract

The invention discloses a pulse copper plating production method with a recovery treatment function. The pulse copper plating production method comprises the following steps of S1, oil removal, S2, hot water cleaning, S3, cold water cleaning, S4, weak etching, S5, activation and acid leaching, S6, pulse copper plating, S7, acid-base neutralization, S8, cold water cleaning and S9, finished product detection. According to the pulse copper plating production method with the recovery processing function, a plating layer circuit board obtained after circuit board oil removal, hot water cleaning, cold water cleaning, weak etching, activation acid leaching and pulse copper plating is taken out, and meanwhile waste liquid in a cleaning tank, a hole conditioning tank, an activation tank, a weak etching tank and a copper plating tank is subjected to recovery processing; the acid-base neutralization is carried out on the waste liquid through a 20% H2SO4 or NaOH solution, so that the waste liquid in the cleaning tank, the hole conditioning tank, the activating tank, the weak etching tank and the copper plating tank can reach the environment-friendly discharge standard, and the waste liquid can be quickly recycled after pulse plating of the circuit board.

Description

Technical Field

[0001] The invention relates to the technical field of pulse copper plating, in particular to a production method of pulse copper plating with a recycling and processing function. Background Art

[0002] Pulse copper plating is an electro-deposition process that uses a motor to pass current to make the metal adhere to the surface of an object. Its purpose is to change the surface state, characteristics and size of the object. At the same time, due to the use of a higher current density during the pulse conduction period, the rate of crystal nucleus formation is much greater than the growth rate of the original crystal, so a finely crystalline coating can be formed. The finely crystalline coating has a high density, high hardness and low porosity.

[0003] However, when pulse copper plating is performed on most circuit boards, it is necessary to add a solution to clean the grease and attachments on the surface of the circuit board, so that the grease and attachments after cleaning will remain in the solution. Directly processing the solution is likely to cause damage to the environment. At the same time, it is not easy to reuse the solution because it contains a lot of grease and attachments. Therefore, it is not easy to recycle the solution when pulse copper plating is performed on the circuit board. Summary of the invention

[0004] The object of the present invention is to provide a pulse copper plating production method with a recycling function to solve the problem that it is not easy to recycle the solution when the circuit board is subjected to pulse copper plating as mentioned in the background art.

[0005] To achieve the above object, the present invention provides the following technical solution: a production method of pulse copper plating with recycling function, comprising the following steps:

[0006] S1. Degreasing: remove grease and other substances from the surface of the circuit board;

[0007] S2, hot water cleaning: put the circuit board, which has been freed of grease, into hot water for cleaning;

[0008] S3, cold water cleaning: the circuit board after hot water cleaning is cleaned again with cold water;

[0009] S4, weak etching: remove the organic film on the copper surface to avoid reducing the bonding force between the base copper layer and the chemical copper plating layer;

[0010] S5, activated acid dip: the circuit board is pre-impregnated and then placed in the activation liquid for activation, so that it can infiltrate the hole wall;

[0011] S6, pulse copper plating: Pd is used as a medium to carry out a reduction reaction on the substrate, copper surface and inside the hole, thereby performing pulse copper plating;

[0012] S7, acid-base neutralization: After the pulse copper plating of the circuit board is completed, the waste liquid of the reaction is collected and then passed through 20% H 2 SO 4 Or NaOH solution for acid-base neutralization, so that the waste liquid can be recycled;

[0013] S8, cold water cleaning: clean the circuit board after the pulse copper plating with cold water, so that the waste liquid residue on the surface can be cleaned, and avoid the waste liquid from adhering to the surface of the circuit board after the plating;

[0014] S9. Finished product inspection: Place the plated circuit board in an oven and bake for 15 minutes to completely dry the surface moisture, and then cool it to room temperature before weighing it.

[0015] Preferably, in S1, the grease is softened and removed by placing the circuit board in an environment of 50-55 degrees.

[0016] Preferably, in S2, the circuit board from which grease and residues have been removed is placed in hot water at 60-65 degrees for cleaning, so that the grease remaining on the surface can be quickly removed.

[0017] Preferably, in S3, after the circuit board is cleaned with hot water, it is rinsed with cold water, so that the surface residues and grease can be completely removed.

[0018] Preferably, in S4, sodium persulfate is added to react with copper so that the organic film on the copper surface can be removed, thereby avoiding reducing the bonding strength between the base copper layer and the chemical copper plating layer.

[0019] Preferably, in S5, an anode phosphor copper ball with a phosphorus content of 1% is activated by acid immersion with acetic acid and degreased with acetone so that the pore wall can be infiltrated.

[0020] Preferably, in S6, Pd is used as a medium to carry out a reduction reaction on the substrate, the copper surface and the inside of the pores, thereby performing pulse copper plating. Pd has catalytic activity and can trigger the occurrence of copper deposition reaction.

[0021] Preferably, in S7, 20% H 2 SO 4 Or NaOH solution is used for acid-base neutralization so that the waste liquid can be recycled and treated. At the same time, the treated waste liquid can be discharged only after testing.

[0022] Preferably, in S8, the circuit board after the pulse copper plating is cleaned with cold water so that the residual waste liquid on the surface can be cleaned to avoid the waste liquid from adhering to the surface of the circuit board after the plating, so that the plating has the advantages of being flat, dense and having good adhesion.

[0023] Preferably, in S9, the plated circuit board is placed in an oven and baked for 15 minutes to completely dry the surface moisture, and then cooled at room temperature and weighed. The cooling time at room temperature is 15 minutes.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: the production method of pulse copper plating with recycling and processing function takes out the plated circuit board obtained after degreasing, hot water cleaning, cold water cleaning, weak etching, activated acid immersion and pulse copper plating of the circuit board, and at the same time, the waste liquid in the cleaning tank, the whole hole tank, the activation tank, the weak etching tank and the copper plating tank is recycled and processed respectively, and the waste liquid is acid-base neutralized by 20% H2SO4 or NaOH solution, so that the waste liquid in the cleaning tank, the whole hole tank, the activation tank, the weak etching tank and the copper plating tank can meet the environmental protection emission standard, so that the circuit board can quickly recycle the waste liquid after pulse plating. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the process structure of the present invention. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] See also Figure 1 The present invention provides a technical solution: a production method of pulse copper plating with recycling function, comprising the following steps:

[0028] S1. Degreasing: remove grease and other substances from the surface of the circuit board;

[0029] S2, hot water cleaning: put the circuit board, which has been freed of grease, into hot water for cleaning;

[0030] S3, cold water cleaning: the circuit board after hot water cleaning is cleaned again with cold water;

[0031] S4, weak etching: remove the organic film on the copper surface to avoid reducing the bonding force between the base copper layer and the chemical copper plating layer. The reaction formula is: Na 2 S 2 O 8 +Cu=Na 2 SO 4 +CuSO 4 ;

[0032] S5, activated acid dip: the circuit board is pre-impregnated and then placed in the activation liquid for activation, so that it can infiltrate the hole wall;

[0033] S6, Pulse copper plating: Pd is used as a medium to carry out reduction reaction on the substrate, copper surface and inside the hole, thereby pulse copper plating is carried out. The cathode reaction after pulse copper plating is: Cu 2+ +2e→Cu 0 The reaction at the anode is: H 2 O→H + +OH - →1 / 2O 2 +2H + +2e - ;

[0034] S7, acid-base neutralization: After the pulse copper plating of the circuit board is completed, the waste liquid of the reaction is collected and then passed through 20% H 2 SO 4 Or NaOH solution for acid-base neutralization, so that the waste liquid can be recycled;

[0035] S8, cold water cleaning: clean the circuit board after the pulse copper plating with cold water, so that the waste liquid residue on the surface can be cleaned, and avoid the waste liquid from adhering to the surface of the circuit board after the plating;

[0036] S9. Finished product inspection: Place the plated circuit board in an oven and bake for 15 minutes to completely dry the surface moisture, and then cool it to room temperature before weighing it.

[0037] Example:

[0038] First, the prepared circuit board is placed in an environment of 50-55 degrees to soften the grease, so that the grease on the surface of the circuit board can be quickly removed. Secondly, it is washed twice with hot water and cold water at 60-65 degrees to remove the residual grease and residue on the surface of the circuit board. Then, sodium persulfate is reacted with copper, so that the organic film on the copper surface can be removed after the reaction, so as to avoid reducing the bonding force between the substrate copper layer and the chemical copper plating layer. Then, the circuit board is placed in an anode phosphorus copper ball with a phosphorus content of 1% and activated with acetic acid, and degreased with acetone so that the hole wall can be infiltrated. Finally, Pd is used as a medium to perform a reduction reaction on the substrate, the copper surface and the hole, thereby performing pulse copper plating, so that the surface of the circuit board can have a better coating after the copper deposition reaction occurs. At the same time, after the circuit board completes the pulse copper plating, the used solution is classified, so that the waste liquid in the cleaning tank, the whole hole tank, the activation tank, the weak corrosion tank and the copper plating tank is respectively passed through 20% H 2 SO 4Or NaOH solution for acid-base neutralization, so that the internal waste liquid can be quickly neutralized to meet the environmental emission requirements, and then the waste liquid can be quickly neutralized to avoid the waste liquid being mixed together and difficult to recycle. Finally, the plated circuit board is rinsed with cold water and placed in an oven for 15 minutes to completely dry the surface moisture, and then it is cooled at room temperature for 15 minutes and weighed to obtain a qualified plated circuit board.

[0039] In summary, after the circuit board is degreased, cleaned with hot water, cleaned with cold water, weakly etched, activated with acid immersion and pulse copper plating, the plated circuit board is taken out, and the waste liquid in the cleaning tank, the hole-filling tank, the activation tank, the weakly etched tank and the copper plating tank is recycled and treated respectively. 2 SO 4 Or NaOH solution is used to neutralize the acid and alkali of the waste liquid, so that the pH value of the waste liquid in the cleaning tank, the whole hole tank, the activation tank, the weak corrosion tank and the copper plating tank can be neutralized to meet the environmental emission standards, so that the circuit board can quickly recycle the waste liquid after pulse plating. The contents not described in detail in this description belong to the existing technology known to professional and technical personnel in this field.

[0040] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A production method of pulse copper plating with recycling function, characterized in that: The following steps are involved: S1. Degreasing: remove grease and other substances from the surface of the circuit board; S2, hot water cleaning: put the circuit board, which has been freed of grease, into hot water for cleaning; S3, cold water cleaning: the circuit board after hot water cleaning is cleaned again with cold water; S4, weak etching: remove the organic film on the copper surface to avoid reducing the bonding force between the base copper layer and the chemical copper plating layer; S5, activated acid dip: the circuit board is pre-impregnated and then placed in the activation liquid for activation, so that it can infiltrate the hole wall; S6, pulse copper plating: Pd is used as a medium to carry out a reduction reaction on the substrate, copper surface and inside the hole, thereby performing pulse copper plating; S7, acid-base neutralization: After the pulse copper plating of the circuit board is completed, the waste liquid of the reaction is collected and then acid-base neutralized by 20% H2SO4 or NaOH solution so that the waste liquid can be recycled; S8, cold water cleaning: clean the circuit board after the pulse copper plating with cold water, so that the waste liquid residue on the surface can be cleaned, and avoid the waste liquid from adhering to the surface of the circuit board after the plating; S9. Finished product inspection: Place the plated circuit board in an oven and bake for 15 minutes to completely dry the surface moisture, and then cool it to room temperature before weighing it.

2. The pulse copper plating production method with recycling function according to claim 1, characterized in that: In S1, the circuit board is placed in an environment of 50-55 degrees to soften and remove the grease.

3. The pulse copper plating production method with recycling function according to claim 1, characterized in that: In S2, the circuit board from which grease and residues have been removed is placed in hot water at 60-65 degrees for cleaning, so that the grease remaining on the surface can be quickly removed.

4. The pulse copper plating production method with recycling function according to claim 1, characterized in that: In S3, after the circuit board is cleaned with hot water, it is rinsed with cold water, and the surface residues and grease can be completely removed.

5. The pulse copper plating production method with recycling function according to claim 1, characterized in that: In S4, sodium persulfate is added to react with copper so that the organic film on the copper surface can be removed, thereby avoiding reducing the bonding force between the base copper layer and the chemical copper plating layer.

6. The pulse copper plating production method with recycling function according to claim 1, characterized in that: In S5, an anode phosphor copper ball with a phosphorus content of 1% is activated by acid immersion with acetic acid and degreased with acetone so that the hole wall can be infiltrated.

7. The pulse copper plating production method with recycling function according to claim 1, characterized in that: In S6, Pd is used as a medium to carry out a reduction reaction on the substrate, the copper surface and the inside of the pores, thereby performing pulse copper plating. Pd has catalytic activity and can trigger the occurrence of copper deposition reaction.

8. The pulse copper plating production method with recycling function according to claim 1, characterized in that: In S7, acid-base neutralization is performed by using 20% ​​H2SO4 or NaOH solution so that the waste liquid can be recycled and processed. Meanwhile, the treated waste liquid can be discharged only after being tested.

9. The pulse copper plating production method with recycling function according to claim 1, characterized in that: In S8, the circuit board after the pulse copper plating is cleaned with cold water so that the residual waste liquid on the surface can be cleaned to avoid the waste liquid from adhering to the surface of the circuit board after the plating, so that the plating layer has the advantages of being flat, dense and having good adhesion.

10. The pulse copper plating production method with recycling function according to claim 1, characterized in that: In S9, the plated circuit board is placed in an oven and baked for 15 minutes to completely dry the surface moisture, and then cooled at room temperature and weighed. The cooling time at room temperature is 15 minutes.

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