A thick-thin mixed crystal composite nickel sulfamate ultra-thin PCB dicing blade and a preparation method thereof

Abstract

The application discloses a kind of thick and thin mixed crystal composite nickel sulfamate ultra-thin PCB scribing knife and preparation method thereof, the present application adopts 1-8 μm fine diamond and 10-50 μm coarse diamond complex structure, give consideration to cutting precision and tool strength.The present application optimizes nickel sulfamate composite plating solution system, introduces cobalt sulfamate to improve coating toughness and abrasive holding force, and cooperates multi-stage substrate pretreatment, fine diamond pre-dispersion, electroplating dynamic addition coarse abrasive and high-low speed alternate stirring process, effectively improves abrasive stratification, coating uneven thickness problem.After machining, alkali etching blade and electrochemical polishing, 12-20 μm ultra-thin scribing knife is obtained.The present application can be adapted to 30000rpm above high-speed cutting condition, edge collapse is small, abrasion is low, service life is long, batch consistency is good, can satisfy the PCB cutting demand of multiple scenes, with good mass production application value.

Description

Technical Field

[0001] This invention relates to the field of dicing blade technology, specifically to a coarse and fine mixed crystal composite nickel aminosulfonate ultrathin PCB dicing blade and its preparation method. Background Technology

[0002] Current PCB cutting nickel-based dicing blades use only a single type of diamond abrasive: fine-grained diamond (1~8μm) offers high cutting precision but suffers from poor rigidity, breakage, and short lifespan; coarse-grained diamond (10~50μm) offers high strength and wear resistance but results in chipping and large burrs. Traditional electroplating processes involve a single-stage diamond input, leading to layering of coarse and fine particles and uneven coating distribution; simplified substrate pretreatment results in coating peeling; coarse parameters in the cutting and polishing processes make it difficult to achieve ultra-thin blades (below 20μm); and high wear and low yield occur during high-speed cutting (above 30,000 rpm). Existing nickel sulfamate electroplating solutions lack cobalt and wetting modification components, resulting in a uniform nickel coating hardness that fails to balance sharpness and gripping power; a single stirring mode causes diamond sedimentation and uneven coating thickness, leading to poor mass production consistency. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a coarse and fine mixed crystal composite nickel aminosulfonate ultrathin PCB dicing blade and its preparation method, so as to solve the problems of coarse and fine particle layering and uneven coating distribution caused by the one-time input of diamond in traditional electroplating process.

[0004] To achieve the above objectives, the present invention provides the following technical solution: S1: Premixing the electroplating solution and dispersing fine diamonds to prepare a composite nickel sulfamate electroplating solution: nickel sulfamate 350~600g / L, nickel chloride 5~30g / L, boric acid 25~55g / L, cobalt sulfamate 40~60g / L, saccharin 0.3~0.6g / L, 1,4-butynediol 0.2~0.5g / L; add 0.1~4g / L of 1~8μm fine diamonds to the plating solution, and continuously circulate and stir using a high- and low-speed adjustable electric stirrer to ensure that the fine diamonds are uniformly suspended and dispersed.

[0005] S2: Multi-stage pretreatment of aluminum alloy substrate S2.1 Alkaline etching: Soak in a mixed alkaline solution of sodium hydroxide, sodium carbonate and sodium silicate for 2 minutes, then rinse with pure water three times; S2.2 Acid etching: Immerse in 50wt% nitric acid aqueous solution for 1 min, then rinse with pure water three times; 3) Zinc immersion activation: Immerse in special zinc immersion solution for 1~10 min, then rinse with pure water three times to remove the oxide film on the aluminum substrate and improve the adhesion of the coating.

[0006] S3: The substrate, after pretreatment, is placed into the plating tank and electroplated in stages with dynamic addition of coarse diamond. The constant DC electroplating is performed at 1.5A. The electroplating process is carried out by alternating high speed (800rpm) and low speed (150rpm). During the electroplating process, 0.1~1g / L of 10~50μm coarse diamond is added to the plating solution every hour. The total electroplating time is 4 hours. Coarse and fine diamonds are co-deposited simultaneously to form a composite coating.

[0007] S4: After machining and electroplating, the substrate is removed, and the inner and outer cylindrical grinding and CNC turning are performed to machine the cutting edge contour, leaving a cutting edge allowance.

[0008] S5: Alkali etching for blade development + electrochemical polishing S5.1 cutting edge: Immerse in 80℃, 250g / L sodium hydroxide cutting edge solution for 10~15min, then rinse three times with water to corrode the aluminum substrate and expose the diamond abrasive grains; S5.2 Polishing: Sulfuric acid-phosphoric acid mixed anodic polishing, constant 32A current polishing for 2 minutes, diamond is fully exposed, and the ultra-thin dicing blade is completed.

[0009] Compared with the prior art, the beneficial effects of the present invention are: 1. Coarse and fine dual diamond compound: fine grains ensure a smooth cutting surface with chipping ≤10μm, while coarse grains enhance coating strength, making the blade less prone to breakage and increasing cutting life by 40%; 2. Adding cobalt sulfamate to the electroplating solution improves the toughness and bonding strength of the nickel-cobalt composite coating, ensuring that the ultra-thin blade does not peel off during high-speed operation; 3. Segmented dynamic coarsening diamond + high and low speed circulating agitation, resulting in no abrasive grain layering, uniform coating, and stable batch performance; 4. Multi-stage aluminum pretreatment + alkaline etching for edge formation + short-time anodizing polishing results in uniform edge formation, ultra-thin cutting edge for stable mass production, and a feed speed of up to 180mm / s.

[0010] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the preferred embodiments of this application are described in detail below with reference to the accompanying drawings.

[0011] The above and other objects, advantages and features of this application will become more apparent to those skilled in the art from the following detailed description of specific embodiments in conjunction with the accompanying drawings. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0013] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a comparison table of embodiments and comparative examples of the present invention. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. In the following description, specific details such as specific configurations and components are provided merely to help fully understand the embodiments of this application. Therefore, those skilled in the art should understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. In addition, for clarity and brevity, descriptions of known functions and structures are omitted in the embodiments.

[0015] Furthermore, reference numerals and / or letters may be repeated in different examples within this application. Such repetition is for the purpose of simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or settings discussed.

[0016] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist simultaneously. The term " / and" in this article describes another type of relationship between related objects, indicating that two relationships can exist. For example, A / and B can mean: A exists alone, and A and B exist alone. In addition, the character " / " in this article generally indicates that the related objects before and after it are in an "or" relationship.

[0017] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion.

[0018] Please see Figure 1-2 This invention provides a technical solution for a coarse-fine mixed-crystal composite nickel aminosulfonate ultrathin PCB dicing blade and its preparation method: Example 1

[0019] This embodiment represents the optimal ratio and process parameter scheme of the present invention, suitable for high-speed and high-precision PCB cutting scenarios.

[0020] (1) Electroplating solution preparation: A composite nickel aminosulfonate system plating solution was adopted, with the specific component ratio being 400 g / L nickel aminosulfonate, 12 g / L nickel chloride, 35 g / L boric acid, 50 g / L cobalt aminosulfonate, 0.4 g / L saccharin, and 0.3 g / L 1,4-butynediol; 0.5 g / L of fine diamond with a particle size of 2 μm was added to the plating solution, and the fine diamond was uniformly pre-dispersed by alternating high and low speed stirring.

[0021] (2) Multi-stage pretreatment of aluminum alloy substrate: A standardized three-stage treatment process is adopted. First, the substrate is soaked in alkaline solution for 2 minutes, and then rinsed with pure water three times. Second, it is acid-etched with 50wt% nitric acid solution for 1 minute, and then rinsed with pure water three times. Finally, it is activated by zinc immersion in special zinc solution for 5 minutes to completely remove the oxide film of the substrate, and then rinsed with pure water three times for later use.

[0022] (3) Electroplating composite process: After the pretreated aluminum alloy substrate is clamped and fixed, it is placed in the plating tank and continuously electroplated for 4 hours with a constant DC current of 1.5A. The electroplating process adopts a high-low speed alternating stirring mode, with circulation parameters of 800rpm high-speed stirring for 15s and 150rpm low-speed stirring for 60s. During the electroplating process, 0.3g / L of coarse diamond with a particle size of 30μm is added to the plating solution every hour to achieve simultaneous co-deposition of coarse and fine diamond.

[0023] (4) Post-processing molding process: After electroplating, the blade contour is processed by internal and external cylindrical grinding and CNC turning, leaving a cutting allowance; then, it is immersed in 80℃, 250g / L sodium hydroxide cutting solution for 12min, and washed with pure water three times; finally, it is anodized for 2min under constant current of 32A using sulfuric acid-phosphoric acid mixture to obtain an ultra-thin PCB dicing blade with a blade thickness of 15μm.

[0024] (5) Performance test results: When cutting PCB boards under standard working conditions of spindle speed of 30000rpm and feed speed of 35mm / s, the blade wear is 5μm per kilometer of outer diameter, the maximum cutting edge chipping is 8μm, and there are no defects such as blade breakage, board surface wire drawing, or blade deformation during the cutting process, and the cutting stability is excellent.

[0025] Example 2

[0026] This embodiment is suitable for cutting high-density, fine-line precision PCBs and integrated circuit packaging substrates, focusing on improving cutting flatness and low edge chipping performance.

[0027] (1) Electroplating solution preparation: The basic components of the plating solution are consistent with the optimal scheme: nickel aminosulfonate 400g / L, nickel chloride 12g / L, boric acid 35g / L, cobalt aminosulfonate 50g / L, saccharin 0.4g / L, 1,4-butynediol 0.3g / L; add 1.0g / L of ultrafine diamond with a particle size of 1μm, and pre-disperse evenly by high and low speed circulation stirring.

[0028] (2) Multi-stage pretreatment of aluminum alloy substrate: alkaline etching for 2 min, three water rinses; acid etching with 50wt% nitric acid for 1 min, three water rinses; zinc immersion activation for 8 min, three pure water rinses to strengthen the adhesion of the substrate coating.

[0029] (3) Electroplating composite process: constant 1.5A DC electroplating for 4 hours, stirring cycle parameters 800rpm / 15s, 150rpm / 60s; 0.2g / L of coarse diamond with a particle size of 20μm is added every hour to refine the coarse abrasive particle size and adapt to the precision cutting requirements.

[0030] (4) Post-processing molding process: After machining, the blade is immersed in 80℃, 250g / L sodium hydroxide solution for 10min, and then washed three times with water; it is anodized with 32A current for 2min, and the thickness of the finished blade is 12μm.

[0031] (5) Performance test results: Under the conditions of 30,000 rpm spindle speed and 35 mm / s feed speed, the wear per kilometer of outer diameter is 6 μm, the maximum cutting edge chipping is 5 μm, the surface finish of the cutting plate is extremely high, and there are no burrs or chipping defects, making it suitable for ultra-high precision cutting scenarios.

[0032] Example 3

[0033] This embodiment is suitable for cutting thick PCBs, multilayer boards, and high-hardness substrates, focusing on improving blade rigidity, wear resistance, and service life, and reducing the risk of blade breakage.

[0034] (1) Electroplating solution preparation: The basic components of the plating solution remain unchanged: nickel aminosulfonate 400g / L, nickel chloride 12g / L, boric acid 35g / L, cobalt aminosulfonate 50g / L, saccharin 0.4g / L, 1,4-butynediol 0.3g / L; add 0.3g / L of fine diamond with a particle size of 8μm, and pre-disperse by stirring at high and low speeds.

[0035] (2) Multi-stage pretreatment of aluminum alloy substrate: alkaline etching for 2 min, three water washes; acid etching with 50wt% nitric acid for 1 min, three water washes; zinc immersion activation for 3 min, three pure water rinses.

[0036] (3) Electroplating composite process: constant 1.5A DC electroplating for 4 hours, with the stirring and circulation parameters unchanged; 0.5g / L of coarse diamond with a particle size of 45μm is added every hour to strengthen the strength and wear resistance of the coating skeleton.

[0037] (4) Post-processing molding process: After machining, the blade is immersed in 80℃, 250g / L sodium hydroxide solution for 15min, and then washed three times with water; it is then anodized with 32A current for 2min, and the finished blade thickness is 18μm.

[0038] (5) Performance test results: Under the conditions of 30,000 rpm spindle speed and 35 mm / s feed speed, the wear per kilometer of outer diameter is 3.5 μm, the maximum cutting edge chipping is 11 μm, the blade rigidity is extremely strong, there are no cracks or broken blades during continuous cutting, the service life is significantly improved, and it is suitable for heavy-duty cutting conditions.

[0039] Comparative Example This comparative example uses the conventional blade manufacturing process in the background technology of traditional patents, and forms a comprehensive comparison with the technical solution of this invention. Except for the core difference parameters, the other processing and testing conditions are completely consistent with the example.

[0040] (1) Electroplating solution preparation: The traditional single nickel-based plating solution is used, without cobalt sulfamate modified components. The specific components are: nickel sulfamate 400g / L, nickel chloride 12g / L, boric acid 35g / L, saccharin 0.4g / L, 1,4-butynediol 0.3g / L; only 0.5g / L of single 2μm fine diamond is added, without coarse diamond compounding.

[0041] (2) Substrate pretreatment, electroplating and posttreatment process: The multi-stage pretreatment process of the substrate, the 1.5A constant current electroplating for 4 hours, the high and low speed stirring mode, the machining, alkaline etching and electrochemical polishing parameters are all completely consistent with those of Example 1, only the plating solution formula and diamond ratio are changed.

[0042] (3) Performance test results: Under the same cutting conditions of 30,000 rpm and 35 mm / s, the blade wears 9 μm of outer diameter per kilometer, the maximum cutting edge chipping is 15 μm, and there are slight burrs on the cutting plate surface; after continuous cutting for 800m, the blade shows fine cracks, and the rigidity and stability are poor, making it unsuitable for long-term high-speed mass production cutting.

[0043] Parallel comparative experiments comparing three sets of differentiated embodiments with traditional processes show that the core technical solution of this invention, which combines coarse and fine mixed crystal diamond, cobalt-modified composite nickel aminosulfonate plating solution, segmented dynamic feeding, and alternating high and low speed stirring, significantly improves the cutting accuracy, wear resistance, structural rigidity, mass production stability, and service life of the blade compared to the traditional single-particle-size, cobalt-free electroplating process. It completely solves the technical problems of traditional ultra-thin dicing blades, such as the inability to balance accuracy and strength, easy edge chipping, easy blade breakage, high wear, and poor batch consistency.

[0044] Traditional processes use a single fine diamond abrasive combined with a cobalt-free nickel-based plating solution, resulting in poor coating toughness, weak abrasive holding power, and significant shortcomings in overall performance. Under the same high-speed cutting conditions, the wear per kilometer of outer diameter reaches as high as 9μm, the maximum cutting edge chipping reaches 15μm, and the cut surface is prone to burrs and wire-like defects, resulting in extremely poor processing accuracy. Furthermore, the structural rigidity is insufficient, and micro-cracks appear on the cutting edge after only 800m of continuous cutting, posing a high risk of blade breakage. It is unsuitable for long-term high-speed mass production cutting scenarios, and its overall performance and stability are extremely poor.

[0045] The three embodiments of this invention, based on a coarse-fine mixed crystal composite structure and a cobalt-modified coating, achieve differentiated performance adaptations to meet the needs of various PCB cutting conditions. Among them, Embodiment 2 is an ultra-fine particle size precision cutting solution, which uses a combination of 1μm fine diamond and 20μm fine-particle-size coarse diamond. The abrasive filling is dense and uniform, and the blade thickness is only 12μm. This can control the maximum cutting edge chipping within 5μm, resulting in optimal surface finish of the cut board without any burrs or chipping defects. It is perfectly adapted to the ultra-high precision cutting scenarios of high-density fine-line PCBs and integrated circuit packaging substrates.

[0046] Example 3 is a high-strength, wear-resistant solution with large-particle size. It uses 8μm fine diamonds combined with 45μm large coarse diamonds. The large-particle coarse diamonds can form a high-strength coating skeleton, which greatly improves the rigidity and wear resistance of the blade body. Its wear per kilometer of outer diameter is only 3.5μm, which is the lowest wear among all test groups. It can continuously cut under heavy loads without cracks or blade breakage, and its service life is greatly improved. It can effectively adapt to the heavy-load cutting conditions of thick PCBs and multi-layer high-hardness substrates, and has excellent resistance to wear and deformation.

[0047] Example 1 represents the optimal comprehensive solution of this invention. It employs a golden ratio of 2μm fine diamond to 30μm coarse diamond, combined with an optimized cobalt-modified plating solution system and standardized process parameters, achieving a balanced and optimal balance of cutting precision, wear resistance, and structural rigidity. This solution features a 15μm blade thickness, suitable for high-speed cutting at 30,000rpm, with a wear of 5μm per kilometer and a maximum edge chipping of 8μm. All performance parameters are well-balanced and excellent, with no defects such as blade breakage, deformation, or wire drawing during the cutting process. It offers optimal mass production stability and compatibility, and can be widely adapted to conventional high-precision PCB high-speed cutting production scenarios.

[0048] Overall test results show that the coarse and fine diamond composite structure can give full play to the dual advantages of fine abrasive cutting and coarse abrasive reinforcement. The cobalt aminosulfonate modified plating solution can effectively improve the toughness and abrasive holding force of nickel-based plating. Combined with multi-stage substrate pretreatment, dynamic feeding and high and low speed alternating stirring process, it completely solves the problems of abrasive delamination, uneven plating, weak bonding force and unstable performance of ultra-thin blades in traditional electroplating processes, and greatly improves the processing yield and service life of ultra-thin PCB dicing blades.

[0049] The above description is merely a preferred embodiment of the present invention and does not limit the scope of protection of the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any changes, modifications, substitutions, integrations, and parameter alterations to these embodiments within the spirit and principles of the present invention, achieved through conventional substitutions or by achieving the same function without departing from the principles and spirit of the present invention, fall within the scope of protection of the present invention.

Claims

1. A coarse-fine mixed-crystal composite nickel aminosulfonate ultrathin PCB dicing blade, characterized in that: It includes an aluminum alloy wheel hub substrate and a composite diamond nickel electroplating layer; the electroplating layer contains both 1~8μm fine diamond particles and 10~50μm coarse diamond particles; the nickel electroplating layer is a nickel-cobalt composite nickel-sulfamate-nickel chloride-boric acid-cobalt-sulfamate coating; the substrate thickness is 10mm, the outer diameter is 56~62mm, and the thickness of the finished blade is 12~20μm.

2. The coarse and fine mixed crystal composite nickel aminosulfonate ultrathin PCB dicing according to claim 1, characterized in that: The fine diamond particles have a diameter of 2 μm, and the coarse diamond particles have a diameter of 30 μm.

3. The preparation method of the coarse and fine mixed crystal composite nickel aminosulfonate ultrathin PCB dicing blade according to any one of claims 1 to 2, characterized in that, Includes the following steps: S1) Prepare a composite nickel sulfamate electroplating solution by adding 1-8 μm fine diamonds to the solution and continuously dispersing them using a high- or low-speed adjustable electric stirrer; the electroplating solution components are: nickel sulfamate 350-600 g / L, nickel chloride 5-30 g / L, boric acid 25-55 g / L, cobalt sulfamate 40-60 g / L, saccharin 0.3-0.6 g / L, 1,4-butynediol 0.2-0.5 g / L; the amount of fine diamonds added is 0.1-4 g / L; S2) Multi-stage pretreatment of aluminum alloy substrate: alkaline etching immersion for 2 min, three water rinses; nitric acid etching for 1 min, three water rinses; zinc immersion for 1~10 min, three water rinses; S3) The substrate is placed into the plating tank using a fixture, and electroplated at a constant current of 1.5A for 4 hours. During the electroplating process, 0.1~1g / L of 10~50μm coarse diamond is added every hour. Stirring is carried out by alternating between high speed of 800rpm and low speed of 150rpm. S4) After electroplating, the outer diameter is ground and the cutting edge is turned. S5) Alkaline etching + electrochemical polishing: Immerse in 80℃ sodium hydroxide etching solution for 10~15 minutes, then rinse with water three times; anoly polish with sulfuric acid-phosphoric acid mixture 32A for 2 minutes to obtain the finished ultra-thin PCB dicing blade.

4. The preparation method according to claim 3, characterized in that: The optimal ratio of the electroplating solution is: nickel sulfamate 400 g / L, nickel chloride 12 g / L, boric acid 35 g / L, cobalt sulfamate 50 g / L, saccharin 0.4 g / L, and 1,4-butynediol 0.3 g / L.

5. The preparation method according to claim 3, characterized in that: The stirring cycle parameters are: high-speed stirring for 15 seconds and low-speed stirring for 60 seconds, alternating between the two.

6. The preparation method according to claim 3, characterized in that: The concentration of sodium hydroxide in the cutting solution is 250 g / L.

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