Lead-free wave welding hole blowing processing procedure control method and application thereof

Abstract

The invention relates to the technical field of the electronic manufacturing industry, in particular to a lead-free wave welding hole blowing machining process control method and application thereof. By limiting the copper deposition degumming treatment rate to be 0.15-0.6 mg / cm < 2 >, it is guaranteed that the backlight grade of the hole wall after copper deposition is larger than or equal to 9, organic matter and pollutants of the hole wall can be effectively removed, the hole wall has proper roughness and activity, the binding force of a copper deposition layer and the hole wall is enhanced, and the hole metallization reliability is improved. During copper electroplating treatment, the current density is set to be 15-25 ASF, the time is controlled to be 20-22 minutes, a copper layer can be evenly and compactly deposited, it is guaranteed that the hole copper thickness reaches the standard, and the conductivity and mechanical performance are improved. And finally, performing windowing treatment on the solder-resisting PTH hole, and by virtue of a reasonable windowing design, assisting solder to be smoothly filled during wave soldering, reducing hole blowing and pseudo soldering, and remarkably improving the welding quality and the production yield.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electronic manufacturing industry, and particularly relates to a lead-free wave solder blow hole processing process control method and application thereof. BACKGROUND

[0002] With the rapid development of electronic industry, as an indispensable key component in electronic equipment, the manufacturing process of printed circuit board (PCB) is also constantly evolving. Among the many manufacturing links of PCB, the soldering process is particularly important, which is directly related to the electrical performance, reliability and service life of electronic equipment. Lead-free tin wave soldering technology has been widely used in the field of electronic manufacturing because it meets environmental requirements and has good soldering performance. However, in the actual production process, lead-free tin wave soldering process faces many challenges, among which the blow hole problem becomes a key problem restricting its further development and application.

[0003] From the perspective of welding principle, when the PCB board is soldered downstream, the moisture of the base material in the broken hole rapidly expands in high temperature to generate a certain air pressure, which blows out the molten tin filled in the hole, thereby forming a "blow hole".

[0004] Blow hole (also known as blow hole) traditionally refers to the existence of broken hole (void) on the finished PTH copper wall. When the PCB board is soldered downstream, it may cause the moisture of the base material in the broken hole to rapidly expand in high temperature to generate a certain air pressure, which blows out the molten tin filled in the hole. After cooling, the tin column in the hole will have a hollow. This poor quality PTH which can blow air is called "blow hole". The blow hole in lead-free wave soldering is related to drilling, PTH and other processes, and also has a great correlation with board material, wave soldering parameters, flux, component pins and the like.

[0005] The blow hole problem of lead-free tin wave soldering seriously affects the production efficiency and product quality of the electronic manufacturing industry, and the existing solutions have many limitations. Therefore, it is of great practical significance and urgent market demand to develop a new technology or method that can effectively solve the blow hole problem of lead-free tin wave soldering. SUMMARY

[0006] The purpose of the present application is to provide a lead-free wave solder blow hole processing process control method and application thereof, which aims to solve the problem that the existing technology cannot realize PTH hole boundary copper plating and glue removal rate and electroplating hole copper thickness compensation value, and prevent pollution risk in the hole.

[0007] To achieve the above application purpose, the technical solution adopted by the present application is as follows:

[0008] In a first aspect, the present application provides a lead-free wave solder blow hole processing process control method, comprising the following steps:

[0009] The sample is treated by copper plating and glue removal, wherein the rate of the copper plating and glue removal is 0.15-0.6 mg / cm2, and the back light level of the hole wall after copper plating is ensured to be ≥9 levels;

[0010] The copper plating treatment is performed, wherein the current density in the step of the copper plating treatment is 15-25 ASF, and the time is 20-22 minutes;

[0011] The PTH hole windowing treatment is further performed.

[0012] In some embodiments, the specific step of the copper plating and glue removal treatment comprises: treating by potassium permanganate at 60-80℃ and pH≥12.

[0013] In some embodiments, the rate of the copper plating and glue removal treatment is controlled by adjusting the regeneration current or the drug concentration in the whole process.

[0014] In some embodiments, the thickness of the copper plating in the copper plating treatment is 5-8 μm.

[0015] In some embodiments, the pattern plating treatment is performed by tin conversion and hot air leveling process, and the thickness of the copper plating is 8-11 μm.

[0016] In some embodiments, the pattern plating treatment is performed by gold conversion, silver conversion and organic solder mask film process, and the thickness of the copper plating is 7-10 μm.

[0017] In some embodiments, the step of the PTH hole windowing treatment comprises: using the film windowing with a pore diameter of 4 mil or the blocking point screen printing technology.

[0018] In the second aspect, the application provides a lead-free wave soldering hole processing process control system, comprising:

[0019] A copper plating and glue removal module for controlling the glue removal rate and the back light level;

[0020] A copper plating compensation module for dynamically adjusting the hole copper thickness;

[0021] A solder mask windowing module for performing the film windowing or the blocking point screen printing design.

[0022] In some embodiments, the copper plating compensation module automatically adjusts the compensation amount of isolated holes and dense holes according to the hole distribution density.

[0023] In some embodiments, the solder mask windowing module comprises an ink coating monitoring unit for real-time detection of the ink thickness and uniformity and feedback adjustment of the process parameters.

[0024] In a third aspect, the application provides a PCB manufactured by the lead-free wave soldering hole processing procedure control method or the lead-free wave soldering hole processing procedure control system.

[0025] The first aspect of the application provides a lead-free wave soldering hole processing procedure control method for a system. By limiting the rate of copper deposition and glue removal treatment to 0.15-0.6 mg / cm 2 , and ensuring that the hole wall back light level after copper deposition is ≥ 9 levels, the organic matter and pollutants on the hole wall can be effectively removed, ensuring that the hole wall surface has good roughness and activity, providing an ideal attachment substrate for subsequent copper deposition, making the copper deposition layer closely combined with the hole wall, reducing defects such as hole wall cavities and fractures, and improving the continuity and integrity of the hole wall copper layer, thereby enhancing the reliability of PCB hole metallization. In the copper electroplating process, the current density is set to 1.8-20 ASF, and the time is controlled to 20-22 minutes, which can make the copper layer uniformly and densely deposited on the hole wall and surface, avoid problems such as uneven copper layer thickness and holes caused by improper current density or insufficient time, ensure that the hole copper thickness meets the requirements, and improve the electrical conductivity and mechanical strength. Finally, the solder mask PTH hole windowing process is performed, laying the foundation for subsequent soldering processes, and reasonable windowing design can ensure that the solder fills the hole smoothly during wave soldering, reduce soldering defects such as hole blowing and false welding, and improve soldering quality and production yield.

[0026] The second aspect of the application provides a lead-free wave soldering hole processing procedure control system, which includes a copper deposition and glue removal module, an electroplating compensation module, and a solder mask windowing module. The copper deposition and glue removal module is specifically used to control the glue removal rate and back light level, and through precise parameter control and real-time monitoring, the hole wall treatment quality is ensured, and a good foundation is provided for subsequent processes. The electroplating compensation module can dynamically adjust the hole copper thickness, and according to different process requirements and hole distribution, more accurate electroplating control is realized, and the problem of uneven copper layer thickness is avoided. The solder mask windowing module performs film windowing or blocking point screen printing design, ensuring the accuracy and quality of windowing. This system realizes modular control of key links in the process, improves the accuracy and automation of process control, can effectively cope with various changing factors in the production process, ensures the stability and reliability of the entire processing procedure, and thus improves the production quality and efficiency of the PCB.

[0027] The PCB provided in the third aspect of the present application is manufactured by using the lead-free wave soldering hole processing method or the control system. In the manufacturing process, the parameter control of each process step and the accurate adjustment of the system module are strictly followed, which can effectively solve the problems of hole wall pollution, uneven copper layer thickness, improper solder mask windowing, etc. in the traditional processing process, significantly reduce the welding defects such as hole blowing, false welding and welding cracking, and improve the conductivity, mechanical strength and welding reliability of the PCB. The PCB manufactured by using the method and the system has higher production yield, more stable performance and longer service life, and can meet the requirements of modern electronic equipment on high reliability, high density and high precision of the PCB, and has wide application prospect and market competitiveness in the electronic information industry. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0029] Figure 1 is a hole blowing slice analysis schematic diagram provided by the embodiments of the present application.

[0030] Figure 2 is a hole blowing slice analysis schematic diagram provided by the embodiments of the present application.

[0031] Figure 3 is a hole blowing slice analysis schematic diagram provided by the embodiments of the present application.

[0032] Figure 4 is a hole blowing slice analysis schematic diagram provided by the embodiments of the present application.

[0033] Figure 5 is a hole blowing slice analysis schematic diagram provided by the embodiments of the present application. DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and beneficial effects of the present application more clearly understood, the present application will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0035] In the present application, the term "and / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. Wherein A and B can be singular or plural. The character " / " generally represents that the associated objects before and after it are in an "or" relationship.

[0036] In this application, "at least one" means one or more, and "multiple" means two or more. "At least one of the following (one)" or similar expressions means any combination of these items, including any combination of single (one) or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can represent a, b, c, a-b (i.e. a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.

[0037] It should be understood that the size of the sequence number of the above-mentioned processes in various embodiments of the present application does not mean the order of execution, and part or all of the steps can be executed in parallel or in sequence, and the execution order of the processes should be determined according to their functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0038] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0039] The weight of the related components mentioned in the embodiments of the present application can not only refer to the specific content of each component, but also represent the weight ratio relationship between each component, therefore, as long as the content of the related components in the embodiments of the present application is enlarged or reduced in proportion, it is within the scope disclosed in the embodiments of the present application. Specifically, the mass mentioned in the embodiments of the present application can be μg, mg, g, kg and other mass units commonly known in the chemical field.

[0040] The terms "first", "second" are only for the purpose of description, used to distinguish objects such as substances from each other, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX can also be called the second XX, and similarly, the second XX can also be called the first XX. Therefore, the features limited by "first" and "second" can explicitly or implicitly include one or more of the features.

[0041] The first aspect of the embodiments of the present application provides a lead-free wave soldering hole processing process control method, comprising the following steps:

[0042] S01. Copper deposition and glue removal treatment is used on the sample, wherein the rate of the copper deposition and glue removal treatment is 0.15-0.6 mg / cm2, and the hole wall back light level after copper deposition is ensured to be ≥9 levels;

[0043] S02. performing a copper electroplating process, wherein, in the step of the copper electroplating process, the current density is 15-25 ASF, and the time is 20-22 minutes;

[0044] S03. further performing a solder mask PTH hole opening process.

[0045] The first aspect of the embodiment of the present application provides a lead-free wave solder hole processing process control method of a system. By limiting the rate of copper deposition and glue removal treatment to 0.15-0.6 mg / cm 2 , and ensuring that the hole wall back light level after copper deposition is ≥ 9 levels, the organic matter and pollutants on the hole wall can be effectively removed, the hole wall surface has good roughness and activity, and an ideal adhesion substrate is provided for subsequent copper deposition, so that the copper deposition layer is closely combined with the hole wall, the defects such as hole wall cavity and fracture are reduced, the continuity and integrity of the copper layer of the hole wall are improved, and the reliability of the PCB hole metallization is enhanced. In the copper electroplating process, the current density is set to 1.8-20 ASF, and the time is controlled to 20-22 minutes, so that the copper layer is uniformly and densely deposited on the hole wall and the surface, the problems such as uneven copper layer thickness and hole caused by improper current density or insufficient time are avoided, the hole copper thickness meets the requirements, and the conductivity and mechanical strength are improved. The solder mask PTH hole opening process performed at the end lays the foundation for the subsequent soldering process, and reasonable opening design can ensure that the solder fills the hole smoothly in the wave soldering process, reduce soldering defects such as hole blowing and virtual welding, and improve the soldering quality and production yield.

[0046] In step S01, the sample is subjected to copper deposition and glue removal treatment, wherein the rate of copper deposition and glue removal treatment is 0.15-0.6 mg / cm2, and the hole wall back light level after copper deposition is ≥ 9 levels. The copper deposition quality is improved, the bonding force is enhanced, and the subsequent copper deposition layer is more closely combined with the hole wall by moderate glue removal to prevent the copper deposition layer from falling off; controlling the glue removal rate helps the copper deposition layer to be uniformly deposited, avoids local copper layer being too thick or too thin, improves the consistency of the hole diameter, reduces the generation of defects such as bubbles in the hole, and reduces the risk of hole blowing caused by uneven copper thickness.

[0047] In some embodiments, the specific steps of the copper deposition and glue removal treatment include: using potassium permanganate at 60-80°C and pH≥12. The specific steps of the copper deposition and glue removal treatment are defined as using potassium permanganate at 60-80°C and pH≥12. Potassium permanganate has stronger oxidizing properties in high-temperature and strong alkaline environments, and can efficiently remove resin drill dirt, colloidal impurities and other impurities on the hole wall, especially for the inner wall of deep holes and high-density holes. High-temperature conditions accelerate the chemical reaction rate, making the glue removal process more complete, and the strong alkaline environment helps to maintain the stability and reactivity of potassium permanganate, ensuring the cleanliness of the hole wall surface and providing a high-quality substrate for the copper deposition process, thereby improving the adhesion of the copper deposition layer to the hole wall, reducing the risk of hole blowing due to hole wall pollution during subsequent welding, and improving the overall performance and reliability of the PCB.

[0048] In some embodiments, the rate of the copper deposition and glue removal treatment is controlled by adjusting the regeneration current or the concentration of the chemical solution in the overall process. The rate of the copper deposition and glue removal treatment is controlled by adjusting the regeneration current or the concentration of the chemical solution in the overall process. This control method has strong flexibility and adaptability, and can adjust the regeneration current or the concentration of the chemical solution in real time according to different production conditions, equipment states, and PCB board materials, hole sizes, etc., to accurately control the glue removal rate and keep it within the ideal range of 0.15-0.6mg / cm 2 This avoids the problems of excessive corrosion of the hole wall due to too fast glue removal rate or incomplete glue removal due to too slow glue removal rate, ensures consistent hole wall treatment effect for each PCB board, improves the stability and repeatability of the process, thereby ensuring the consistency of the copper deposition quality, reducing product defects caused by fluctuations in the glue removal process, and improving production efficiency and product yield.

[0049] In step S02, the copper plating treatment is performed, wherein the current density in the copper plating treatment step is 15-25 ASF and the time is 20-22 minutes. The copper plating hole thickness compensation technology can accurately control the thickness of the hole copper, ensure that the copper thickness of each PTH hole meets the process requirements, and at the same time reduce the dependence on the drilling accuracy. Even if there are certain defects or holes in the drilling process, such as drill bit wear, drilling deviation, etc., the thick copper guide can also compensate for it, thereby reducing the high requirement for drilling accuracy and improving the flexibility and efficiency of production.

[0050] In some embodiments, the electroplated copper thickness of the electroplating copper process is 5-8 μm. A suitable hole copper thickness is a key factor to ensure the electrical conductivity and mechanical strength of the PCB board. If the copper layer is too thin, it may lead to insufficient electrical conductivity, insufficient mechanical strength of the hole wall, and prone to breakage, open circuit and other problems during welding and use; if the copper layer is too thick, it will increase the material cost and electroplating time, and may also lead to uneven copper layer in the hole. Controlling the thickness to be 5-8 μm can meet the requirements of electrical conductivity and mechanical strength, and also take into account production efficiency and cost. A uniform and dense copper layer can effectively conduct current, withstand thermal stress and mechanical stress during the welding process, reduce welding defects and product failures caused by improper copper layer thickness, and improve the reliability and service life of the PCB board.

[0051] In some embodiments, the electroplated copper thickness of the electroplating copper process is 8-11 μm. When using the tin removal and hot air leveling process, the electroplated copper thickness is 8-11 μm. The tin removal and hot air leveling process has a higher requirement for the thickness of the copper layer. A thicker copper layer can withstand high temperature processing and subsequent welding process, ensure good bonding force between the tin layer and the copper layer, and avoid problems such as tin layer falling off and solder cracking.

[0052] In some embodiments, the electroplated copper thickness of the electroplating copper process is 7-10 μm. When using the gold removal, silver removal and organic solder mask film process, the electroplated copper thickness is 7-10 μm. These processes have relatively low requirements for the thickness of the copper layer. An appropriate thickness can not only ensure the stability of the combination of the surface plating layer and the copper layer, but also save material costs. This differentiated thickness control allows the electroplating process to better adapt to the needs of different surface treatment processes, improves the quality and reliability of the plating layer, meets the needs of various product application scenarios, and improves the overall performance of the PCB board.

[0053] In step S03, the PTH hole windowing process is further performed. The solder mask precision is improved, and the ink printing position is accurately controlled. The blocking point screen printing technology can accurately print the solder mask ink at the predetermined position through special screen design and accurate alignment system, avoid the ink entering the PTH hole; at the same time, reduce the ink diffusion and penetration, which can effectively control the printing thickness and area of the solder mask ink, make the edge of the solder mask layer more neat, reduce the pollution to the surrounding of the PTH hole, improve the solder mask quality and stability, maintain the cleanliness and integrity of the hole wall, which is beneficial to the subsequent welding process.

[0054] In some embodiments, the step of solder mask PTH hole windowing processing includes using a film windowing aperture of 4 mil or a barrier point screen printing technology. In the step of solder mask PTH hole windowing processing, a film windowing aperture of 4 mil or a barrier point screen printing technology is used. The film windowing aperture of 4 mil can accurately control the windowing size of the solder mask ink, ensure that the pads are completely exposed, and avoid the problem that the pads cannot be fully covered by the solder due to too small windowing, or the problem that the ink covers the hole wall due to too large windowing, affecting the welding effect. The barrier point screen printing technology can form a uniform solder mask layer around the hole, prevent the ink from entering the hole, and ensure the neatness of the hole edge. Both of these technologies can effectively avoid the interference of the solder mask ink on the welding area in the hole, ensure that the solder can smoothly flow into the hole during wave soldering, discharge the gas in the hole, reduce welding defects such as blowhole and bridging, improve the reliability and consistency of the solder joints, and improve the welding quality and production yield of the PCB board.

[0055] The second aspect of the embodiments of the present application provides a lead-free wave soldering blowhole processing process control system, comprising:

[0056] A copper plating and glue removal module is used to control the glue removal rate and the backlight level.

[0057] A plating compensation module is used to dynamically adjust the hole copper thickness.

[0058] A solder mask windowing module is used to perform film windowing or barrier point screen printing design.

[0059] The lead-free wave soldering blowhole processing process control system provided by the second aspect of the embodiments of the present application comprises a copper plating and glue removal module, a plating compensation module, and a solder mask windowing module. The copper plating and glue removal module is specially used to control the glue removal rate and the backlight level, and through accurate parameter control and real-time monitoring, the hole wall processing quality is ensured, and a good foundation is provided for subsequent processes. The plating compensation module can dynamically adjust the hole copper thickness, realize more accurate plating control according to different process requirements and hole distribution, and avoid the problem of uneven copper thickness. The solder mask windowing module performs film windowing or barrier point screen printing design to ensure the accuracy and quality of windowing. This system realizes modular control of key links in the process, improves the accuracy and automation degree of process control, can effectively cope with various change factors in the production process, ensures the stability and reliability of the entire processing process, and thus improves the production quality and efficiency of the PCB board.

[0060] In some embodiments, the electroplating compensation module automatically adjusts the compensation amount of isolated holes and dense holes according to the hole distribution density. On a PCB board, the electroplating environment around isolated holes and dense holes is different. Due to the influence of current distribution and chemical solution flow, the hole copper in the dense hole area is prone to be thin, while the isolated hole may cause the copper layer to be too thick due to current concentration. The electroplating compensation module automatically performs different compensation processing on isolated holes and dense holes by identifying the hole distribution density, so that the copper layer thickness of isolated holes is appropriately reduced, and the copper layer thickness of dense holes is improved, thereby ensuring that the copper layer thickness of all holes is uniform, avoiding electroplating defects caused by differences in hole distribution, improving the uniformity and consistency of hole copper thickness, and enhancing the overall performance and reliability of the PCB board.

[0061] In some embodiments, the solder mask windowing module includes an ink coating monitoring unit for real-time detection of ink thickness and uniformity, and feedback adjustment of process parameters. During the solder mask windowing process, the thickness and uniformity of the ink directly affect the quality of the windowing and the solder mask effect. The ink coating monitoring unit can monitor the coating of the ink in real time. Once it is found that the thickness is uneven or does not meet the requirements, the information is fed back to the control system in time, and the coating process parameters such as screen pressure, doctor blade speed, ink viscosity, etc. are automatically adjusted to ensure uniform coating of the ink, accurate windowing size, avoid problems such as poor pad coverage and ink residue in the hole caused by ink coating problems, improve the precision and reliability of the solder mask process, thereby reducing soldering defects and improving the production quality of the PCB board.

[0062] The third aspect of the embodiments of the present application provides a PCB board manufactured by the above-mentioned lead-free wave soldering hole processing process control method or the above-mentioned lead-free wave soldering hole processing process control system.

[0063] The PCB board provided by the third aspect of the embodiments of the present application is manufactured by the above-mentioned lead-free wave soldering hole processing process control method or control system. Because the parameter control of each process step and the accurate adjustment of the system module are strictly followed during the manufacturing process, the problems commonly encountered in traditional processing, such as hole wall pollution, uneven copper layer thickness, and improper solder mask windowing, can be effectively solved, soldering defects such as hole blowing, virtual welding, and solder cracking are significantly reduced, and the conductive performance, mechanical strength, and soldering reliability of the PCB board are improved. The PCB board manufactured by the method and system has higher production yield, more stable performance, and longer service life, and can meet the requirements of modern electronic equipment for high reliability, high density, and high precision of the PCB board, and has a wide application prospect and market competitiveness in the electronic information industry.

[0064] The following will be described in conjunction with specific embodiments.

[0065] Embodiment 1

[0066] A lead-free wave soldering hole processing process control method, comprising the following steps:

[0067] The sample was treated with copper plating and degumming, wherein the rate of the copper plating and degumming treatment was 0.15-0.6 mg / cm 2 , and ensure that the backlight level of the hole wall after copper deposition is ≥ level 9; the specific steps of the copper deposition degumming treatment include: using potassium permanganate for treatment at 60-80°C and pH ≥ 12, and the rate of the copper deposition degumming treatment is controlled by adjusting the regeneration current or the concentration of the solution in the overall process.

[0068] Perform copper electroplating treatment, wherein, in the step of copper electroplating treatment, the current density is 15-25ASF, and the time is 20-22 minutes; adopt tin electroplating and hot air leveling process for pattern electroplating treatment, and the thickness of the electroplated copper is 8-11μm; or adopt gold electroplating, silver electroplating and organic solderability film process for pattern electroplating treatment, and the thickness of the electroplated copper is 7-10μm.

[0069] Then perform solder mask PTH hole window opening processing.

[0070] The thickness of the electroplated copper in the electroplating process is 5-8 μm, and the step of opening the solder mask PTH hole window includes: using a film window that is 4 mil larger than the hole diameter or a dot screen printing technology.

[0071] In summary, the embodiment of the present application provides a systematic lead-free wave soldering hole blowing process control method. By limiting the copper plating degumming treatment rate to 0.15-0.6 mg / cm 2 , and ensuring the hole wall backlight level is ≥ Level 9 after copper plating. This effectively removes organic matter and contaminants from the hole wall, ensuring a good roughness and active surface, providing an ideal adhesion base for subsequent copper plating. This ensures a tight bond between the copper layer and the hole wall, reduces defects such as voids and fractures in the hole wall, and improves the continuity and integrity of the copper layer in the hole wall, thereby enhancing the reliability of the PCB hole metallization. During the copper electroplating process, setting the current density to 1.8-20ASF and the time to 20-22 minutes ensures a uniform and dense deposition of the electroplated copper layer on the hole wall and surface, avoiding problems such as uneven copper layer thickness and voids caused by improper current density or insufficient time, ensuring that the hole copper thickness meets the requirements, and improving conductivity and mechanical strength. The final solder mask PTH hole window treatment lays the foundation for subsequent soldering processes. A reasonable window design ensures smooth solder filling during the wave soldering process, reducing solder defects such as blowholes and cold solder joints, and improving soldering quality and production yield.

[0072] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A lead-free wave soldering hole blowing process control method, characterized in that: The steps include: The sample was treated with copper plating and degumming, wherein the rate of the copper plating and degumming treatment was 0.15-0.6 mg / cm 2 , and ensure that the backlight level of the hole wall after copper deposition is ≥ level 9; Performing copper electroplating treatment, wherein, in the step of copper electroplating treatment, the current density is 15-25ASF and the time is 20-22 minutes; Then perform solder mask PTH hole window opening processing.

2. The lead-free wave soldering hole blowing process control method according to claim 1, characterized in that: The specific steps of the copper plating degumming treatment include: using potassium permanganate to treat at 60-80° C. and pH ≥12.

3. The lead-free wave soldering hole blowing process control method according to claim 1, characterized in that: The rate of the copper plating and degumming treatment is controlled in the overall process by adjusting the regeneration current or the concentration of the chemical solution.

4. The lead-free wave soldering hole blowing process control method according to claim 1, characterized in that: The thickness of the electroplated copper in the electroplating copper process is 5-8 μm.

5. The lead-free wave soldering hole blowing process control method according to claim 4, characterized in that: Using tinning and hot air leveling process to carry out pattern electroplating treatment, the thickness of the electroplated copper is 8-11 μm; and / or, The pattern electroplating process is carried out by adopting chemical gold, chemical silver and organic solderability protection film process, and the thickness of the electroplated copper is 7-10 μm.

6. The lead-free wave soldering hole blowing process control method according to claim 4, characterized in that: The steps of opening the solder mask PTH hole include: using film opening 4 mil larger than the hole diameter or screen printing technology.

7. A lead-free wave soldering hole blowing process control system, characterized in that: include: Copper deposition and degumming module, used to control the degumming rate and backlight level; Electroplating compensation module, used to dynamically adjust hole copper thickness; Solder mask window module, used to perform film window or screen printing design.

8. The system according to claim 7, characterized in that The electroplating compensation module automatically adjusts the compensation amount of isolated holes and dense holes according to the hole distribution density.

9. The system according to claim 7 or 8, characterized in that The solder resist window module includes an ink coating monitoring unit for real-time detection of ink thickness and uniformity, and feedback adjustment of process parameters.

10. A PCB board, characterized in that: The lead-free wave soldering hole blowing process control method according to any one of claims 1-6 or the lead-free wave soldering hole blowing process control system according to any one of claims 7-9 is used for manufacturing.

Images