Circuit board black hole process and circuit board

Abstract

The invention provides a circuit board black hole process and a circuit board. The black hole process for the circuit board comprises the following steps of: soaking the circuit board in a first hole conditioning cylinder to perform first hole conditioning treatment so as to improve the adhesiveness of the hole wall of the circuit board to a conductive substance; the circuit board is soaked in a first black hole cylinder for first black hole processing, so that a conductive layer is formed on the hole wall of the circuit board; soaking the circuit board in a second hole conditioning cylinder to perform second hole conditioning treatment so as to improve the adhesiveness of the conductive layer to the conductive substance; soaking the circuit board in a second black hole cylinder to perform second black hole processing so as to increase the thickness of the conductive layer; cleaning the circuit board to remove the liquid medicine on the surface of the circuit board; and carrying out copper plating treatment on the circuit board, so that the surface of the conductive layer is covered with a copper layer.

Description

Technical Field

[0001] The present invention relates to the field of black holes in circuit boards, and in particular to a circuit board black hole process and a circuit board. Background Art

[0002] The black hole process of circuit boards refers to the process of evenly dispersing fine graphite or carbon black powder in a medium, namely deionized water, and using the surfactant in the solution to keep the graphite or carbon black suspension in a stable and uniform manner. The surfactant also has good wetting properties, so that the graphite or carbon black can be fully adsorbed on the surface of the non-conductor hole wall to form a uniform, fine and firmly bonded conductive layer.

[0003] In traditional technology, the black hole steps of circuit boards are cleaning, hole filling, and black hole. For example, Chinese patent application number CN201410322778.4 discloses a black hole horizontal production line process flow and a black hole slot structure, and its process flow includes the following steps: cleaning, black hole one, hole filling, black hole two, micro-etching, anti-oxidation, and discharging. In order to make the graphite and carbon black powder more evenly adhere to the hole wall of the circuit board, the above patent adopts two black hole steps, that is, two black hole cylinders are used to soak the circuit board. In the actual production process, the black hole cylinder needs to be replaced regularly to remove the waste liquid and clean the impurities in the cylinder, and add new black hole liquid into the new cylinder. In order to improve production efficiency, two black hole cylinders are usually replaced on the production line at the same time, that is, new black hole liquid is added to the two black hole cylinders. Since the black hole liquid in the cylinder is static when it is just added, it has not undergone mechanical circulation of temperature and equipment, resulting in poor activity of the black hole liquid in the two black hole cylinders, which makes the circuit board and the liquid not react fully, and then the conductive layer formed in the hole of the circuit board is uneven, making the copper layer of the circuit board after electroplating like Figure 2 , Figure 3 As shown, there are problems of thin hole copper and hole copper fracture.

[0004] Therefore, there is an urgent need for a circuit board black hole process that can make the thickness of the conductive layer in the hole uniform and avoid hole copper breakage. Summary of the invention

[0005] The purpose of the present disclosure is to overcome the deficiencies in the prior art and provide a circuit board black hole process and a circuit board that can make the thickness of the conductive layer in the hole uniform and avoid the breakage of the hole copper.

[0006] The purpose of this disclosure is achieved through the following technical solutions:

[0007] A circuit board black hole process, comprising the following steps:

[0008] Immersing the circuit board in a first hole-smoothing tank to perform a first hole-smoothing treatment to improve the adhesion of the hole wall of the circuit board to the conductive material;

[0009] Immersing the circuit board in a first black hole tank to perform a first black hole treatment, so that a conductive layer is formed on the hole wall of the circuit board;

[0010] Immersing the circuit board in a second hole-smoothing tank to perform a second hole-smoothing treatment to improve the adhesion of the conductive layer to the conductive material;

[0011] Immersing the circuit board in a second black hole tank to perform a second black hole treatment to increase the thickness of the conductive layer;

[0012] Cleaning the circuit board to remove the liquid medicine on the surface of the circuit board;

[0013] Performing copper plating on the circuit board so that the surface of the conductive layer is covered with a copper layer;

[0014] Wherein, before the first hole-sizing process is performed on the circuit board, the following steps are also included:

[0015] Performing a cylinder cleaning process on the first whole hole cylinder;

[0016] The second whole hole cylinder is subjected to a cylinder cleaning process, wherein there is a first preset interval time between the cylinder cleaning process of the first whole hole cylinder and the cylinder cleaning process of the second whole hole cylinder, and the first preset interval time is greater than N process cycles of the circuit board black hole process, where N is an integer greater than 1;

[0017] Before the circuit board is subjected to the first black hole treatment, the following steps are also included:

[0018] Performing a cleaning process on the first black hole cylinder;

[0019] The second black hole cylinder is cleaned, and there is a second preset interval time between the cleaning of the first black hole cylinder and the cleaning of the second black hole cylinder. The second preset interval time is greater than M process cycles of the circuit board black hole process, and M is an integer greater than 1.

[0020] In one embodiment, the first preset interval is 1 day to 3 days; and / or,

[0021] The second preset interval time is April to June.

[0022] In one embodiment, the first black hole cylinder is cleaned, specifically comprising the following steps:

[0023] Discharge 1 / 2-1 / 3 of the volume ratio of the old liquid in the first black hole cylinder, seal the old liquid, and pass the old liquid into the second black hole cylinder when cleaning the second black hole cylinder;

[0024] New liquid having the same volume as the old liquid discharged is introduced into the first black hole cylinder so that the new liquid is mixed with the old liquid.

[0025] In one embodiment, the first whole hole cylinder is cleaned, specifically comprising the following steps:

[0026] Drain the old liquid in the first whole hole cylinder;

[0027] Performing a cleaning operation on the first whole hole cylinder;

[0028] The new liquid is introduced into the first whole hole cylinder.

[0029] In one embodiment, the cleaning operation of the first whole hole cylinder specifically includes the following steps:

[0030] flushing the first whole hole cylinder with an organic solvent to dissolve dirt in the first whole hole cylinder;

[0031] The first whole-hole cylinder is rinsed with deionized water to remove organic solvents and dirt in the first whole-hole cylinder.

[0032] In one embodiment, the time of the first hole-smoothing treatment is T 1 , the T 1 The time of the second hole treatment is T 2 , the T 2 is 45s-60s, and T 2 Greater than T 1 and / or,

[0033] The time of the first black hole treatment is T 3 , the T 3 The second black hole treatment time is T 4 , the T 4 is 60s-90s, and T 4 Greater than T 3 .

[0034] In one embodiment, the circuit board is cleaned, specifically comprising the following steps:

[0035] Using deionized water to rinse the circuit board to remove the residual liquid on the surface of the circuit board;

[0036] The circuit board is baked at a high temperature to evaporate the moisture on the surface of the circuit board.

[0037] In one embodiment, the circuit board is immersed in a second hole-sizing tank to perform a second hole-sizing treatment, and the following steps are also included:

[0038] The ultrasonic device is activated to oscillate the liquid medicine in the second whole hole cylinder.

[0039] In one embodiment, the circuit board is cleaned, and the following steps are also included before the cleaning process:

[0040] A micro-etching operation is performed on the circuit board to roughen the surface of the conductive layer.

[0041] A circuit board is prepared by using the circuit board black hole process described in any of the above embodiments.

[0042] Compared with the prior art, the present invention has at least the following advantages:

[0043] In the above-mentioned circuit board black hole process, the circuit board is subjected to the first hole-sizing treatment in the first hole-sizing cylinder, and the second hole-sizing treatment is carried out in the second hole-sizing cylinder. The impurities on the surface of the circuit board are removed through the two hole-sizing treatments, and the adhesion of the hole wall of the circuit board to the carbon powder is improved. Then, the circuit board is subjected to the first black hole treatment in the first black hole cylinder, and the second black hole treatment is carried out in the second black hole cylinder. The two black hole treatments make the conductive layer formed on the hole wall of the circuit board more uniform. Furthermore, the activity of the newly added liquid medicine after cleaning the cylinder is higher or lower than that of the liquid medicine in the cylinder that has not been cleaned. This is because the new liquid medicine is sealed in the barrel and is in a static state. When the liquid medicine is just added to the cylinder after cleaning, it has not undergone temperature and production line circulation, resulting in the activity of the newly added liquid medicine after cleaning being lower than that of the liquid medicine in the cylinder that has not been cleaned. There is a first preset interval time for the cleaning treatment of the first whole hole cylinder and the second whole hole cylinder, that is, the cleaning of the first whole hole cylinder and the second whole hole cylinder is staggered, so that the activities of the liquid medicine in the first whole hole cylinder and the second whole hole cylinder are staggered and complementary, thereby making the whole hole treatment of the circuit board more perfect. Similarly, there is a second preset interval time for the cleaning treatment of the first black hole cylinder and the second black hole cylinder, that is, the cleaning of the first black hole cylinder and the second black hole cylinder is staggered, so that the activities of the liquid medicine in the first black hole cylinder and the second black hole cylinder are staggered and complementary, thereby making the black hole treatment of the circuit board more perfect, thereby making the thickness of the conductive layer formed in the hole of the circuit board more uniform, so as to avoid the problem of breakage or uneven thickness of the copper layer formed after copper plating of the conductive layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 A process flow chart of a circuit board black hole process according to an embodiment;

[0046] Figure 2 This is a physical picture of the copper hole in the circuit board prepared by traditional technology;

[0047] Figure 3 Another physical picture of the copper hole of the circuit board prepared by the traditional process;

[0048] Figure 4 To adopt Figure 1 The physical picture of the copper hole prepared by the black hole process of the circuit board shown;

[0049] Figure 5 To adopt Figure 1 Another physical picture of the copper holes prepared by the black hole process of the circuit board shown. DETAILED DESCRIPTION

[0050] In order to facilitate the understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present disclosure are given in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thoroughly and comprehensively understood.

[0051] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present disclosure. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0053] The present invention provides a circuit board black hole process, comprising the following steps: immersing the circuit board in a first hole-forming cylinder to perform a first hole-forming treatment to improve the adhesion of the hole wall of the circuit board to the conductive material; immersing the circuit board in the first black hole cylinder to perform a first black hole treatment to form a conductive layer on the hole wall of the circuit board; immersing the circuit board in a second hole-forming cylinder to perform a second hole-forming treatment to improve the adhesion of the conductive layer to the conductive material; immersing the circuit board in a second black hole cylinder to perform a second black hole treatment to increase the thickness of the conductive layer; cleaning the circuit board to remove the conductive layer on the circuit board. The surface of the circuit board is treated with a chemical solution; the circuit board is copper-plated so that the surface of the conductive layer is covered with a copper layer; wherein, before the first hole-filling treatment is performed on the circuit board, the following steps are also included: the first hole-filling cylinder is cleaned; the second hole-filling cylinder is cleaned, and there is a first preset interval between the first hole-filling cylinder cleaning and the second hole-filling cylinder cleaning; before the first black hole treatment is performed on the circuit board, the following steps are also included: the first black hole cylinder is cleaned; the second black hole cylinder is cleaned, and there is a second preset interval between the first black hole cylinder cleaning and the second black hole cylinder cleaning.

[0054] In the above-mentioned circuit board black hole process, the circuit board is subjected to the first hole-sizing treatment in the first hole-sizing cylinder, and the second hole-sizing treatment is carried out in the second hole-sizing cylinder. The impurities on the surface of the circuit board are removed through the two hole-sizing treatments, and the adhesion of the hole wall of the circuit board to the carbon powder is improved. Then, the circuit board is subjected to the first black hole treatment in the first black hole cylinder, and the second black hole treatment is carried out in the second black hole cylinder. The two black hole treatments make the conductive layer formed on the hole wall of the circuit board more uniform. Furthermore, the activity of the newly added liquid medicine after cleaning the cylinder is higher or lower than that of the liquid medicine in the cylinder that has not been cleaned. This is because the new liquid medicine is sealed in the barrel and is in a static state. When the liquid medicine is just added to the cylinder after cleaning, it has not undergone temperature and production line circulation, resulting in the activity of the newly added liquid medicine after cleaning being lower than that of the liquid medicine in the cylinder that has not been cleaned. There is a first preset interval time for the cleaning treatment of the first whole hole cylinder and the second whole hole cylinder, that is, the cleaning of the first whole hole cylinder and the second whole hole cylinder is staggered, so that the activities of the liquid medicine in the first whole hole cylinder and the second whole hole cylinder are staggered and complementary, thereby making the whole hole treatment of the circuit board more perfect. Similarly, there is a second preset interval time for the cleaning treatment of the first black hole cylinder and the second black hole cylinder, that is, the cleaning of the first black hole cylinder and the second black hole cylinder is staggered, so that the activities of the liquid medicine in the first black hole cylinder and the second black hole cylinder are staggered and complementary, thereby making the black hole treatment of the circuit board more perfect, thereby making the thickness of the conductive layer formed in the hole of the circuit board more uniform, so as to avoid the problem of breakage or uneven thickness of the copper layer formed after copper plating of the conductive layer.

[0055] In order to better understand the technical solutions and beneficial effects of the present invention, the present invention is further described in detail below in conjunction with specific embodiments:

[0056] like Figure 1 As shown, a circuit board black hole process according to an embodiment includes the following steps:

[0057] S100: Soaking the circuit board in a first hole-smoothing tank to perform a first hole-smoothing treatment to improve the adhesion of the hole wall of the circuit board to the conductive material.

[0058] In this embodiment, the circuit board after the hole is opened is immersed in the first hole-smoothing cylinder. The first hole-smoothing liquid is provided in the hole-smoothing liquid. The hole-smoothing liquid has certain cleaning and leveling functions. It can remove impurities and pollutants on the hole wall and provide a clean and flat surface for the deposition of conductive materials. At the same time, the hole-smoothing liquid also contains cationic surfactants to eliminate the electrostatic repulsion between the substrate surface and the negatively charged carbon colloid in the black hole liquid, promote the physical adsorption of carbon colloid particles on the hole wall, and facilitate the conductive material (graphite or carbon black, etc.) in the black hole liquid to adhere to the hole wall more evenly.

[0059] S200: Soaking the circuit board in a first black hole tank to perform a first black hole treatment, so that a conductive layer is formed on the hole wall of the circuit board.

[0060] In this embodiment, the circuit board after the whole hole is immersed in the first black hole cylinder, and the first black hole cylinder is provided with a black hole liquid, and the black hole liquid contains conductive materials such as graphite or carbon black. The effect of the surfactant in the black hole liquid is utilized to keep the graphite or conductive carbon black suspension stable and have good wetting properties. When the circuit board is immersed in the black hole liquid in the first black hole cylinder, the graphite or carbon black can be adsorbed on the non-conductive hole wall surface to preliminarily form a thin conductive layer.

[0061] S300: Soaking the circuit board in a second hole-smoothing tank to perform a second hole-smoothing treatment to improve the adhesion of the conductive layer to the conductive material.

[0062] In this embodiment, the circuit board after the first black hole treatment is immersed in the second hole wholeing cylinder, and the second hole wholeing cylinder is provided with a hole wholeing liquid. The composition of the hole wholeing liquid in the second hole wholeing cylinder is basically the same as that of the first hole wholeing cylinder. The concentration of the cationic surfactant in the second hole wholeing cylinder is relatively high, that is, the first hole wholeing treatment is more for cleaning the circuit board surface, and the second hole wholeing treatment is to use a high concentration of cationic surfactant to better eliminate the electrostatic repulsion between the substrate surface and the negatively charged carbon colloid in the black hole liquid, so that in the subsequent secondary black hole treatment process, the conductive material is better attached to the initially formed conductive layer, thereby forming a more uniform and dense conductive layer.

[0063] S400: Soaking the circuit board in a second black hole tank to perform a second black hole treatment to increase the thickness of the conductive layer.

[0064] It is understandable that the thickness and density of the conductive layer in the hole of the circuit board after the first black hole treatment do not meet the requirements. If copper plating is directly performed at this time, it is easy to cause leakage or non-plating, reducing the reliability of the black hole process. Therefore, in this embodiment, the circuit board after the second hole whole-hole treatment is immersed in the second black hole cylinder for the second black hole treatment. The black hole liquid in the second black hole cylinder has a higher concentration of graphite and surfactant than the black hole liquid in the first black hole cylinder, so that on the basis of forming a thinner conductive layer in the first black hole treatment, the second black hole treatment can increase the thickness of the conductive layer and make the conductive layer more dense, which is helpful for the copper layer to evenly cover the hole wall in the subsequent copper plating process.

[0065] S500: Cleaning the circuit board to remove the liquid medicine on the surface of the circuit board.

[0066] In this embodiment, the circuit board after the secondary black hole treatment is cleaned to remove the residual liquid medicine on the surface of the circuit board to prevent the liquid medicine from entering the copper plating tank and affecting the adhesion of the copper layer. Furthermore, a high-pressure water gun can be used to rinse the surface of the circuit board so that the water flow can enter the holes of the circuit board to remove the residual liquid medicine in the holes.

[0067] S600: copper plating the circuit board so that the surface of the conductive layer is covered with a copper layer.

[0068] In this embodiment, the circuit board is placed in a copper plating tank and powered on. The copper ions in the copper plating tank are adsorbed into the holes of the circuit board. The copper ions form copper impurities on the surface of the conductive layer and adhere to it, so that a copper layer is plated in the holes of the circuit board, making the conductive performance in the holes of the circuit board more stable.

[0069] In one embodiment, before performing the first hole-filling process on the circuit board, the following steps are also included:

[0070] Performing a cylinder cleaning process on the first whole hole cylinder;

[0071] The second whole hole cylinder is cleaned, and there is a first preset interval time between the cleaning of the first whole hole cylinder and the cleaning of the second whole hole cylinder. The first preset interval time is greater than N process cycles of the circuit board black hole process, and N is an integer greater than 1.

[0072] It is understandable that the first whole-hole cylinder and the second whole-hole cylinder need to be cleaned after being used for a period of time. This is because dirt and residue will be generated in the whole-hole cylinder after long-term use, which will affect the activity and concentration of the medicine. In traditional technology, in order to improve the efficiency of cleaning the cylinder, the first whole-hole cylinder and the second whole-hole cylinder are usually cleaned at the same time. However, the new medicine is sealed in the barrel and is in a static state. When the new medicine is introduced into the whole-hole cylinder after cleaning, the activity of the medicine at this time is relatively low because it has not undergone temperature and production line circulation. That is, the activity of the newly introduced medicine needs to reach a peak value after a period of time. If the first whole-hole cylinder and the second whole-hole cylinder are cleaned at the same time, the activity of the medicine in the first whole-hole cylinder and the second whole-hole cylinder will be in a low state at this time. Therefore, in this embodiment, there is a first preset interval time between the cleaning treatment of the first whole hole cylinder and the second whole hole cylinder, that is, the cleaning of the first whole hole cylinder and the second whole hole cylinder is staggered. For example, the first whole hole cylinder is cleaned first, and the activity of the liquid medicine in the first whole hole cylinder is relatively low at this time, but the second whole hole cylinder is not cleaned at this time, that is, the activity of the liquid medicine in the second whole hole cylinder is relatively high, so that the liquid medicine activities of the first whole hole treatment and the second whole hole treatment are complementary, so that the circuit board can complete the whole hole treatment normally. After the first preset interval time, the second whole hole cylinder is cleaned again, and the liquid medicine activity of the first whole hole cylinder is higher than that of the second whole hole cylinder, so that the liquid medicine activities of the first whole hole treatment and the second whole hole treatment are complementary, so that the circuit board can complete the whole hole treatment normally. Further, the first preset interval time is greater than N process cycles of the circuit board black hole process, and N is an integer greater than 1, indicating that the interval time between the cleaning of the first whole hole cylinder and the second whole hole cylinder is greater than the time for the circuit board to perform the black hole process.

[0073] In one embodiment, before performing the first black hole treatment on the circuit board, the following steps are also included:

[0074] Performing a cleaning process on the first black hole cylinder;

[0075] The second black hole cylinder is cleaned, and there is a second preset interval time between the cleaning of the first black hole cylinder and the cleaning of the second black hole cylinder. The second preset interval time is greater than M process cycles of the circuit board black hole process, and M is an integer greater than 1.

[0076] It is understandable that the first black hole cylinder and the second black hole cylinder need to be cleaned after being used for a period of time. This is because the black hole cylinders will also produce dirt and residues after long-term use, which will affect the concentration and activity of the liquid medicine. In traditional technology, in order to improve the efficiency of cleaning, the first black hole cylinder and the second black hole cylinder are usually cleaned at the same time. However, the new black hole liquid is sealed in the barrel and is in a static state. When the new black hole liquid is passed into the black hole cylinder after cleaning, it has not undergone temperature and production line circulation, resulting in relatively low activity of the black hole liquid at this time. That is, the activity of the newly introduced black hole liquid needs to reach a peak value after a period of time. If the first black hole cylinder and the second black hole cylinder are cleaned at the same time, the activity of the black hole liquid in the first black hole cylinder and the second black hole cylinder will be in a low state at this time. Therefore, in this embodiment, there is a second preset interval time for the cleaning treatment of the first black hole cylinder and the second black hole cylinder, that is, the cleaning of the first black hole cylinder and the second black hole cylinder is staggered. For example, the first black hole cylinder is cleaned first, and the activity of the black hole liquid in the first black hole cylinder is relatively low at this time, but the second black hole cylinder is not cleaned at this time, that is, the activity of the black hole liquid in the second black hole cylinder is relatively high, so that the activities of the black hole liquid in the first black hole treatment and the second black hole treatment are complementary, so that the circuit board can complete the black hole treatment normally. After the second preset interval time, the second black hole cylinder is cleaned again, and at this time, the activity of the liquid in the first black hole cylinder has reached a peak after being recycled for a period of time, that is, the activity of the black hole liquid in the first black hole cylinder is relatively high at this time, so that the activities of the black hole liquid in the first black hole treatment and the second black hole treatment are complementary, so that the circuit board can complete the black hole treatment normally. Further, the second preset interval time is greater than N process cycles of the circuit board black hole process, and N is an integer greater than 1, indicating that the interval time between the cleaning of the first black hole cylinder and the second black hole cylinder is greater than the time for the circuit board to perform the black hole process.

[0077] In the above-mentioned circuit board black hole process, the circuit board is subjected to the first hole-sizing treatment in the first hole-sizing cylinder, and the second hole-sizing treatment is carried out in the second hole-sizing cylinder. The impurities on the surface of the circuit board are removed through the two hole-sizing treatments, and the adhesion of the hole wall of the circuit board to the carbon powder is improved. Then, the circuit board is subjected to the first black hole treatment in the first black hole cylinder, and the second black hole treatment is carried out in the second black hole cylinder. The two black hole treatments make the conductive layer formed on the hole wall of the circuit board more uniform. Furthermore, the activity of the newly added liquid medicine after cleaning the cylinder is higher or lower than that of the liquid medicine in the cylinder that has not been cleaned. This is because the new liquid medicine is sealed in the barrel and is in a static state. When the liquid medicine is just added to the cylinder after cleaning, it has not undergone temperature and production line circulation, resulting in the activity of the newly added liquid medicine after cleaning being lower than that of the liquid medicine in the cylinder that has not been cleaned. There is a first preset interval time for the cleaning treatment of the first whole hole cylinder and the second whole hole cylinder, that is, the cleaning of the first whole hole cylinder and the second whole hole cylinder is staggered, so that the activities of the liquid medicine in the first whole hole cylinder and the second whole hole cylinder are staggered and complementary, thereby making the whole hole treatment of the circuit board more perfect. Similarly, there is a second preset interval time for the cleaning treatment of the first black hole cylinder and the second black hole cylinder, that is, the cleaning of the first black hole cylinder and the second black hole cylinder is staggered, so that the activities of the liquid medicine in the first black hole cylinder and the second black hole cylinder are staggered and complementary, thereby making the black hole treatment of the circuit board more perfect, thereby making the thickness of the conductive layer formed in the hole of the circuit board more uniform, so as to avoid the problem of breakage or uneven thickness of the copper layer formed after copper plating of the conductive layer.

[0078] In one embodiment, the first preset interval time is 1 day to 3 days. It can be understood that the first preset interval time is 1 day to 3 days, that is, the second whole hole cylinder is cleaned 1 day to 3 days after the first whole hole cylinder is cleaned, so that the liquid in the first whole hole cylinder has a higher activity after being recycled for a preset time, and the second whole hole cylinder is replaced at this time, so that the liquid in the first whole hole cylinder and the second whole hole cylinder complement each other, so that the circuit board can complete the whole hole treatment normally.

[0079] In one embodiment, the second preset interval is 4-6 months. It can be understood that the second preset interval is 4 to 6 months, that is, the second black hole cylinder is cleaned 4 to 6 months after the first black hole cylinder is cleaned, so that the black hole liquid in the second black hole cylinder has a higher activity after being recycled for a preset time. At this time, the second whole hole cylinder is replaced, so that the black hole liquids of the first black hole cylinder and the second black hole cylinder complement each other, so that the circuit board can complete the black hole treatment normally.

[0080] In one embodiment, the first black hole cylinder is cleaned, specifically comprising the following steps:

[0081] Discharge 1 / 2-1 / 3 of the volume ratio of the old liquid in the first black hole cylinder, seal the old liquid, and pass the old liquid into the second black hole cylinder when cleaning the second black hole cylinder;

[0082] New liquid having the same volume as the old liquid discharged is introduced into the first black hole cylinder so that the new liquid is mixed with the old liquid.

[0083] It is understandable that when the first black hole cylinder is cleaned, if the old liquid in the first black hole cylinder is completely discharged, the amount of liquid medicine used will increase, which will lead to an increase in cost. In this embodiment, 1 / 2-1 / 3 of the volume ratio of the old liquid in the first black hole cylinder is discharged, and the old liquid is sealed in a storage tank for storage. The old liquid is used to pass into the second black hole cylinder during the cleaning process. This is because the composition of the liquid medicine in the first black hole cylinder and the second black hole cylinder is basically the same. For the cleaning process of the second black hole cylinder, since the second black hole cylinder has passed 1 / 2-1 / 3 of the volume ratio of the old liquid, the second black hole cylinder only needs to pass the corresponding new liquid to mix with the old liquid, that is, the second black hole cylinder does not need to pass all the new liquid, thus reducing the amount of liquid medicine used in the second black hole cylinder during the cleaning process. Furthermore, with respect to the cleaning treatment of the first black hole cylinder, since the first black hole cylinder discharges 1 / 2-1 / 3 of the volume of old liquid, it is only necessary to introduce a corresponding volume of new liquid to mix with the old liquid in the first black hole cylinder, that is, there is no need to introduce all the new liquid into the first black hole cylinder, thereby reducing the amount of medicine used in the cleaning of the first black hole cylinder. Simultaneously, since 1 / 2-2 / 3 of the volume of old liquid remains in the first black hole cylinder, the old liquid has been circulated through the temperature and production line, that is, the activity of the old liquid is relatively high. The old liquid is mixed with the new liquid with lower activity to form the black hole liquid in the first black hole cylinder. Compared with the first black hole cylinder in which all the new liquid is introduced, the black hole liquid mixed with the remaining part of the old liquid and the new liquid has relatively higher activity. In this way, while improving the activity of the medicine in the first black hole cylinder, it can also save the use of medicine, reduce production costs, and make the effect of the first black hole treatment better. Furthermore, when the second black hole cylinder is being cleaned, a portion of the old liquid in the second black hole cylinder can be discharged to be introduced into the first black hole cylinder during the cleaning process, so that the amount of new liquid introduced into the first black hole cylinder can be further reduced during the cleaning process, and the old liquid in the first black hole cylinder and the second black hole cylinder is continuously circulated, so that the amount of new liquid used can be reduced, and the activity of the liquid in the first black hole cylinder and the second black hole cylinder after cleaning can be simultaneously ensured. Furthermore, in order to facilitate the cleaning of the first black hole cylinder, the old liquid in the first black hole cylinder can be introduced into a temporary storage tank, at which time the liquid in the first black hole cylinder is completely discharged, and the cylinder wall of the first black hole cylinder is cleaned with an organic solvent and clean water to remove the residue in the first black hole cylinder, and then the old liquid in the temporary storage tank is introduced into the first black hole cylinder, and a corresponding volume of new liquid is introduced synchronously, so that new black hole liquid is formed in the first black hole cylinder.

[0084] In one embodiment, the first whole hole cylinder is cleaned, specifically comprising the following steps:

[0085] Drain the old liquid in the first whole hole cylinder;

[0086] Performing a cleaning operation on the first whole hole cylinder;

[0087] The new liquid is introduced into the first whole hole cylinder.

[0088] In this embodiment, the old liquid in the first whole hole cylinder is pumped out by a pressure pump, and then the dirt and residue in the first whole hole cylinder are rinsed with deionized water to remove the dirt and residue, and finally the new whole hole liquid is passed into the first whole hole cylinder by a pressure pump to complete the cleaning process of the first whole hole cylinder. Furthermore, the cleaning process of the second whole hole cylinder, the first black hole cylinder and the second black hole cylinder is the same as the cleaning process of the first whole hole cylinder, which will not be repeated here.

[0089] In one embodiment, the cleaning operation of the first whole hole cylinder specifically includes the following steps:

[0090] flushing the first whole hole cylinder with an organic solvent to dissolve dirt in the first whole hole cylinder;

[0091] The first whole-hole cylinder is rinsed with deionized water to remove organic solvents and dirt in the first whole-hole cylinder.

[0092] It is understandable that since the residues and dirt in the first whole-hole cylinder are mainly resin, grease, metal debris, etc., these residues and dirt adhere to the cylinder wall of the first whole-hole cylinder, and simply deionizing flushing may not be able to completely remove these residues and dirt. In this embodiment, an organic solvent (such as hydrocarbons, alcohols and other chemical reagents) is first added to the cylinder. The organic solvent has a strong dissolving ability and can dissolve the grease, resin and other dirt in the whole-hole cylinder. Then, the first whole-hole cylinder is rinsed with deionized water at high pressure to remove the dirt and the organic solvent together, so that the cleaning of the first whole-hole cylinder is more thorough.

[0093] In one embodiment, the time of the first hole-smoothing treatment is T 1 , the T 1 The time of the second hole treatment is T 2 , the T 2 is 45s-60s, and T 2 Greater than T 1 .

[0094] In this embodiment, the time T of the first hole-sizing treatment is 1 The second hole treatment time is 45s-60s. 2 is 45s-60s, and T2 Greater than T 1 This is because a thinner conductive layer is formed after the first black hole treatment, and the second pore-forming treatment takes a longer time to allow more cations in the pore-forming liquid to accumulate on the conductive layer and the pore wall to improve the adhesion of the conductive material, thereby making the conductive layer formed after the second black hole thicker, more uniform and denser.

[0095] In one embodiment, the first black hole treatment time is T 3 , the T 3 The second black hole treatment time is T 4 , the T 4 is 60s-90s, and T 4 Greater than T 3 .

[0096] In this embodiment, the time T of the first black hole treatment is 3 The second black hole treatment time is 60s-90s. 4 is 60s-90s, and T 4 Greater than T 3 , so that the conductive material can be better gathered on the hole wall of the circuit board during the second black hole treatment, thereby making the conductive layer formed after the second black hole thicker, more uniform and more dense.

[0097] In one embodiment, the circuit board is cleaned, specifically comprising the following steps:

[0098] Using deionized water to rinse the circuit board to remove the residual liquid on the surface of the circuit board;

[0099] The circuit board is baked at a high temperature to evaporate the moisture on the surface of the circuit board.

[0100] In this embodiment, the circuit board is rinsed with deionized water by a high-pressure water gun so that the water can flow into the holes of the circuit board to remove the residual liquid medicine in the holes. After washing, the circuit board is dried at high temperature by a drying device to quickly evaporate the moisture on the dry surface of the circuit board.

[0101] In one embodiment, the circuit board is immersed in a second hole-sizing tank to perform a second hole-sizing treatment, and the following steps are also included:

[0102] The ultrasonic device is activated to oscillate the liquid medicine in the second whole hole cylinder.

[0103] It can be understood that in order to ensure that the liquid medicine in the second whole hole cylinder can fully contact the hole wall of the circuit board during the second whole hole treatment, an ultrasonic device is used to oscillate the liquid medicine in the second whole hole cylinder, so that the whole hole liquid forms turbulence in the second whole hole cylinder, thereby making the whole hole liquid fully contact and wet the hole wall, thereby making the effect of the second whole hole treatment better.

[0104] In one embodiment, the circuit board is immersed in a second black hole tank to perform a second black hole treatment to increase the thickness of the conductive layer, and the following steps are also included:

[0105] The ultrasonic device is activated to vibrate the liquid medicine in the second black hole cylinder.

[0106] It can be understood that in order to make the conductive layer after the second black hole treatment more uniform and denser, when the circuit board is immersed in the second black hole cylinder, the ultrasonic equipment is started to vibrate the black hole liquid in the second black hole cylinder, so that the black hole liquid forms turbulence in the second black hole cylinder, thereby making the black hole liquid contact with the hole wall more fully, thereby making the effect of the second black hole treatment better.

[0107] In one embodiment, the circuit board is cleaned, and the following steps are also included before the cleaning process:

[0108] A micro-etching operation is performed on the circuit board to roughen the surface of the conductive layer.

[0109] It can be understood that in order to make the copper better adhere to the conductive layer in the copper plating process, in this embodiment, an etching liquid is used to perform a micro-etching operation on the circuit board, that is, the etching liquid will bite and etch the surface of the conductive layer, thereby increasing the roughness of the surface of the conductive layer, and then increasing the bonding force between the conductive layer and the copper layer, so that the copper is better adhered to the conductive layer to form a copper layer with more uniform thickness and better density.

[0110] It is understandable that the thickness of the conductive layer formed in the hole of the circuit board needs to be within a preset range. This is because if the thickness of the conductive layer is small, the effect of the copper layer adhering to the conductive layer in the subsequent copper plating process is poor, resulting in a low thickness of the copper layer, which in turn leads to poor conductivity in the hole of the circuit board. If the thickness of the conductive layer is high, the resistance in the hole will be high, which will also affect the conductivity in the hole of the circuit board. Therefore, in order to make the thickness of the conductive layer in the hole more suitable, in one embodiment, the circuit board is immersed in a second black hole tank for a second hole-smoothing treatment, and the following steps are also included before:

[0111] Obtaining a first thickness of a conductive layer in a circuit board hole;

[0112] matching a first thickness of the conductive layer with a first preset thickness;

[0113] When the first thickness of the conductive layer is greater than or equal to the first preset thickness, the concentration of the black hole solution in the second black hole treatment is reduced, and the temperature of the black hole solution in the second black hole treatment is increased.

[0114] In this embodiment, the first thickness is the thickness of the conductive layer initially formed after the first black hole treatment of the circuit board, and the first preset thickness is the appropriate thickness range value pre-set after the first black hole treatment of the circuit board. If the first thickness is not within the first preset thickness range, it will affect the thickness of the conductive layer after the secondary black hole treatment, and further affect the conductive effect in the hole of the circuit board. Specifically, the thickness of the conductive layer in the hole of the circuit board is first detected to obtain a first thickness, and the first thickness is matched with a first preset thickness. When the first thickness is greater than or equal to the first preset thickness, it indicates that the thickness of the conductive layer after the first black hole treatment is relatively high. In this case, the reaction parameters of the second black hole treatment need to be adjusted so that the final thickness of the conductive layer is within a preset range. By reducing the concentration of the black hole liquid in the second black hole treatment, that is, reducing the content of graphite and carbon black in the black hole liquid, the amount of graphite and carbon black collected in the hole of the circuit board during the second black hole treatment is reduced. Simultaneously, the temperature of the black hole liquid in the second black hole treatment is increased. This is because the active temperature of the black hole liquid is generally 20°C to 25°C. Increasing the temperature of the black hole liquid will also reduce the activity of the black hole liquid. In this way, the thickness of the conductive layer formed by the second black hole treatment is relatively low, that is, the conductive layer after the first black hole treatment and the second black hole treatment is within a preset range, thereby making the conductive effect in the hole of the circuit board better.

[0115] In another embodiment, when the first thickness of the conductive layer is less than the first preset thickness, the concentration of the black hole solution in the second black hole treatment is increased, and the temperature of the black hole solution in the second black hole treatment is decreased.

[0116] In this embodiment, when the first thickness of the conductive layer is less than the first preset thickness, it indicates that the thickness of the conductive layer formed by the first black hole treatment is low, and the reaction parameters of the second black hole treatment need to be adjusted to increase the thickness of the conductive layer formed by the second black hole treatment. Specifically, by increasing the concentration of the black hole liquid in the second black hole treatment, that is, increasing the content of graphite and carbon black in the black hole liquid, the amount of graphite and carbon black collected in the circuit board holes during the second black hole treatment is increased, and at the same time, the temperature of the black hole liquid in the second black hole treatment is reduced to make the temperature of the black hole liquid lower, so that the activity of the black hole liquid is greater, and thus the thickness of the conductive layer formed by the second black hole treatment is greater, and thus the conductive layer after the first black hole treatment and the second black hole treatment is within the preset range.

[0117] Furthermore, in order to ensure that the thickness of the conductive layer after the second black hole treatment is within a preset range, so that the conductive effect in the circuit board hole is good and the resistance is low, in one embodiment, the circuit board is immersed in a second black hole tank to perform a second hole treatment, and then the following steps are further included:

[0118] Obtaining a second thickness of the conductive layer in the circuit board hole;

[0119] Matching the second thickness of the conductive layer with the second preset thickness

[0120] When the second thickness is greater than or equal to the second preset thickness, the concentration of the etching solution in the micro-etching operation is increased to reduce the reaction time of the micro-etching operation.

[0121] In this embodiment, the second thickness is the sum of the conductive layer after the first black hole treatment and the second black hole treatment, and the second preset thickness is the thickness of the conductive layer in the circuit board hole after the black hole treatment. It can be understood that if the second thickness is less than the second preset thickness, it indicates that the thickness of the formed conductive layer is low, so that the conductive effect in the circuit board hole is poor. If the second thickness is greater than the second preset thickness, it indicates that the thickness of the formed conductive layer is high, so that the resistance in the circuit board hole is large. Specifically, the thickness of the conductive layer in the circuit board hole is first detected to obtain the second thickness, and then the second thickness is matched with the second preset thickness. When the second thickness is greater than or equal to the second preset thickness, it indicates that the thickness of the formed conductive layer is high at this time. At this time, by increasing the concentration of the etching solution in the micro-etching operation, the etching solution is used to bite the conductive layer to roughen the surface of the conductive layer. Increasing the concentration of the etching solution increases the effect of the etching solution on the conductive layer, so that the thickness of the conductive layer bitten increases, and then the thickness of the conductive layer after etching is reduced, so that the thickness of the conductive layer finally formed on the circuit board is within the second preset thickness range. Furthermore, it is necessary to reduce the reaction time of the etching operation. This is because increasing the concentration of the etching solution may affect the copper layer and dry film on the circuit board surface. If the etching operation time is too long, the etching solution will corrode the copper layer and dry film on the circuit board surface, thereby affecting the circuit on the circuit board surface. By reducing the reaction time of the etching operation, the etching solution will not affect the circuit board surface while corroding the conductive layer.

[0122] The present application also provides a circuit board, which is prepared using the circuit board black hole process described in any of the above embodiments.

[0123] Compared with the prior art, the present invention has at least the following advantages:

[0124] In the above-mentioned circuit board black hole process, the circuit board is subjected to the first hole-sizing treatment in the first hole-sizing cylinder, and the second hole-sizing treatment is carried out in the second hole-sizing cylinder. The impurities on the surface of the circuit board are removed through the two hole-sizing treatments, and the adhesion of the hole wall of the circuit board to the carbon powder is improved. Then, the circuit board is subjected to the first black hole treatment in the first black hole cylinder, and the second black hole treatment is carried out in the second black hole cylinder. The two black hole treatments make the conductive layer formed on the hole wall of the circuit board more uniform. Furthermore, the activity of the newly added liquid medicine after cleaning the cylinder is higher or lower than that of the liquid medicine in the cylinder that has not been cleaned. This is because the new liquid medicine is sealed in the barrel and is in a static state. When the liquid medicine is just added to the cylinder after cleaning, it has not undergone temperature and production line circulation, resulting in the activity of the newly added liquid medicine after cleaning being lower than that of the liquid medicine in the cylinder that has not been cleaned. There is a first preset interval time for the cleaning treatment of the first whole hole cylinder and the second whole hole cylinder, that is, the cleaning of the first whole hole cylinder and the second whole hole cylinder is staggered, so that the activities of the liquid medicine in the first whole hole cylinder and the second whole hole cylinder are staggered and complementary, thereby making the whole hole treatment of the circuit board more perfect. Similarly, there is a second preset interval time for the cleaning treatment of the first black hole cylinder and the second black hole cylinder, that is, the cleaning of the first black hole cylinder and the second black hole cylinder is staggered, so that the activities of the liquid medicine in the first black hole cylinder and the second black hole cylinder are staggered and complementary, thereby making the black hole treatment of the circuit board more perfect, thereby making the thickness of the conductive layer formed in the hole of the circuit board more uniform, so as to avoid the problem of breakage or uneven thickness of the copper layer formed after copper plating of the conductive layer.

[0125] The above-described embodiments only express several implementation methods of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in the field, several modifications and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the patent of the present disclosure shall be subject to the attached claims.

Claims

1. A circuit board black hole process, characterized in that: The following steps are involved: Immersing the circuit board in a first hole-smoothing tank to perform a first hole-smoothing treatment to improve the adhesion of the hole wall of the circuit board to the conductive material; Immersing the circuit board in a first black hole tank to perform a first black hole treatment, so that a conductive layer is formed on the hole wall of the circuit board; Immersing the circuit board in a second hole-smoothing tank to perform a second hole-smoothing treatment to improve the adhesion of the conductive layer to the conductive material; Immersing the circuit board in a second black hole tank to perform a second black hole treatment to increase the thickness of the conductive layer; Cleaning the circuit board to remove the liquid medicine on the surface of the circuit board; Performing copper plating on the circuit board so that the surface of the conductive layer is covered with a copper layer; Wherein, before the first hole-sizing process is performed on the circuit board, the following steps are also included: Performing a cylinder cleaning process on the first whole hole cylinder; The second whole hole cylinder is subjected to a cylinder cleaning process, wherein there is a first preset interval time between the cylinder cleaning process of the first whole hole cylinder and the cylinder cleaning process of the second whole hole cylinder, and the first preset interval time is greater than N process cycles of the circuit board black hole process, where N is an integer greater than 1; Before the circuit board is subjected to the first black hole treatment, the following steps are also included: Performing a cleaning process on the first black hole cylinder; The second black hole cylinder is cleaned, and there is a second preset interval time between the cleaning of the first black hole cylinder and the cleaning of the second black hole cylinder. The second preset interval time is greater than M process cycles of the circuit board black hole process, and M is an integer greater than 1.

2. The circuit board black hole process according to claim 1, characterized in that: The first preset interval time is 1 day to 3 days; and / or, The second preset interval time is April to June.

3. The circuit board black hole process according to claim 1, characterized in that: The first black hole cylinder is cleaned, specifically comprising the following steps: Discharge 1 / 2-1 / 3 of the volume ratio of the old liquid in the first black hole cylinder, seal the old liquid, and pass the old liquid into the second black hole cylinder when cleaning the second black hole cylinder; New liquid having the same volume as the old liquid discharged is introduced into the first black hole cylinder so that the new liquid is mixed with the old liquid.

4. The circuit board black hole process according to claim 1, characterized in that: The first whole hole cylinder is cleaned, specifically comprising the following steps: Drain the old liquid in the first whole hole cylinder; Performing a cleaning operation on the first whole hole cylinder; The new liquid is introduced into the first whole hole cylinder.

5. The circuit board black hole process according to claim 4, characterized in that: The first whole hole cylinder is cleaned, specifically comprising the following steps: flushing the first whole hole cylinder with an organic solvent to dissolve dirt in the first whole hole cylinder; The first whole-hole cylinder is rinsed with deionized water to remove organic solvents and dirt in the first whole-hole cylinder.

6. The circuit board black hole process according to claim 1, characterized in that: The time of the first hole-smoothing treatment is T1, and T1 is 45s-60s; the time of the second hole-smoothing treatment is T2, and T2 is 45s-60s, and T2 is greater than T1; and / or, The time for the first black hole treatment is T3, and T3 is 60s-90s. The time for the second black hole treatment is T4, and T4 is 60s-90s, and T4 is greater than T3.

7. The circuit board black hole process according to claim 1, characterized in that: The circuit board is cleaned, specifically comprising the following steps: Using deionized water to rinse the circuit board to remove the residual liquid on the surface of the circuit board; The circuit board is baked at a high temperature to evaporate the moisture on the surface of the circuit board.

8. The circuit board black hole process according to claim 1, characterized in that: The circuit board is immersed in a second hole-sizing tank to perform a second hole-sizing treatment, and the method further includes the following steps: The ultrasonic device is activated to oscillate the liquid medicine in the second whole hole cylinder.

9. The circuit board black hole process according to claim 1, characterized in that: The circuit board is cleaned, and the following steps are also included before the cleaning process: A micro-etching operation is performed on the circuit board to roughen the surface of the conductive layer.

10. A circuit board, characterized in that: The circuit board black hole process according to any one of claims 1 to 9 is used for preparation.

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