Electroplating dicing blade and preparation method thereof

Abstract

The invention belongs to the technical field of semiconductor processing, and relates to an electroplating dicing blade and a preparation method thereof. The preparation method provided by the invention comprises the following steps: firstly, forming a photoresist layer on the surface of a substrate subjected to surface treatment, and after the photoresist layer is subjected to exposure and development process treatment, forming a graphical window corresponding to the target shape of a scribing knife; carrying out nickel-diamond composite electroplating on the area with the graphical window by taking the substrate as a cathode until a plating layer with a preset thickness is formed; then removing the photoresist layer, and separating the formed dicing blade from the substrate; and performing electrolytic treatment on the scribing knife to expose the diamond particles, and inspecting to obtain a finished product. Compared with a traditional electroplating and multi-channel machining process, the photoetching patterning and electroplating forming method provided by the invention has the advantages that the production efficiency, the machining precision, the product yield and the performance are comprehensively and remarkably improved, and a revolutionary solution is provided for manufacturing of high-end precision electroplated cutters.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor processing technology and relates to an electroplating scribing blade and its preparation method. Background Technology

[0002] With the rapid development of the semiconductor industry, integrated circuit (IC) packaging technology is constantly evolving towards smaller size, better performance, and lower power consumption, such as advanced packaging forms like DFN, QFN, and BGA. In the dicing process of IC packaged products, electroplated diamond dicing blades are widely used due to their strong bonding force on diamond, long service life, and good cutting effect.

[0003] Traditional electroplated dicing blade manufacturing processes typically require multiple machining steps, including internal drilling and cooling tank fabrication, after the formation of a nickel-diamond composite layer through electroplating. This subsequent processing can take 2-3 days. These machining steps not only result in low production efficiency and extended product delivery times, but each step also generates a certain number of defective products due to mechanical stress and positioning errors, making it difficult to improve the overall yield rate. Furthermore, the machining precision is limited, usually only controllable within ±10μm, which is insufficient to meet higher precision cutting requirements.

[0004] Therefore, there is an urgent need in this field for a new method for preparing electroplated scribing blades that can simplify the production process and improve accuracy and yield. Summary of the Invention

[0005] Based on this, the purpose of this invention is to provide a method for preparing an electroplated dicing blade. This method uses photolithography and composite electroplating processes to prepare the electroplated dicing blade in one step, eliminating the need for subsequent cumbersome machining and significantly improving production efficiency and product precision.

[0006] The present invention also provides an electroplated scribing blade prepared by the method, which has high product consistency, can effectively reduce the impact and chipping of the workpiece during cutting, improve the cutting quality, and reduce costs.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a method for preparing an electroplated scribing blade, comprising the following steps: S1, a photoresist layer is formed on the pre-treated substrate A to obtain substrate B; the photoresist layer on substrate B is subjected to exposure treatment and development treatment in sequence to form a patterned window corresponding to the target shape of the dicing blade to obtain substrate C. S2, using the substrate C described in S1 as the cathode and the nickel plate as the anode; performing nickel-diamond composite electroplating in the area with the patterned window to form a coating, thus obtaining substrate D; S3, the photoresist layer on the substrate D described in S2 is removed, and the formed dicing blade is peeled off from the substrate D; the peeled dicing blade is subjected to electrolytic treatment to obtain the electroplated dicing blade.

[0008] Furthermore, the pretreated substrate A mentioned in S1 is a stainless steel or aluminum alloy substrate with a surface roughness Ra of 1.6 to 0.4.

[0009] Furthermore, the pretreatment process of substrate A is as follows: first, substrate A is ultrasonically cleaned with an alkaline cleaning agent at 55~65℃ for 8~15 minutes to thoroughly remove oil, and then rinsed with deionized water; subsequently, substrate A is fixed on a surface grinder and finely ground with a diamond grinding wheel of 1400~1600 grit under constant pressure, and finally the surface roughness Ra is controlled at 1.6~0.4.

[0010] After pretreatment, substrate A achieves a mirror-like matte finish, ensuring adhesion of the subsequent photoresist and providing an ideal substrate for high-precision pattern transfer. Appropriate roughness ensures good adhesion between the photoresist and the substrate, guarantees the accuracy of the photolithographic pattern, and facilitates smooth peeling by the dicing blade after electroplating. Excessive substrate roughness leads to decreased product precision, defects, or difficulty in peeling. Insufficient roughness reduces coating adhesion, increases the risk of blistering and peeling during the process, and excessive polishing incurs unnecessary costs.

[0011] Furthermore, the photoresist layer described in S1 is formed by coating followed by drying. The photoresist used includes a positive photoresist suitable for UV broadband exposure, preferably a positive photoresist suitable for g / h / i line exposure (e.g., AZ). ® P4620, AZ ® 5214).

[0012] Furthermore, the coating is performed by spin coating, and the spin coating parameters are as follows: first, the photoresist is spread at a low speed of 450~550 rpm for a period of time, and then at a high speed of 2000~2500 rpm for a period of time to form a photoresist film of the target thickness. The target thickness is consistent with the thickness of the dicing blade, and is usually selected as 0.005~0.5mm. Preferably, for a 4-inch substrate, the amount of photoresist coated each time is about 3~5mL. By adjusting the spin coating speed, the uniformity of film thickness can be precisely controlled.

[0013] Furthermore, after coating is completed, the substrate is immediately moved to a hot plate for pre-baking (soft baking), that is, baked at 100±0℃ for 1~3 minutes to completely remove solvent and stabilize the film.

[0014] Further, the exposure process described in S1 is as follows: first, a quartz photomask with a dicing blade negative image pattern is bonded to substrate B, and then exposure is performed using a UV light source with a power of 1±0.2kW, with an exposure dose of 140~160mJ / cm. 2 UV light passes through a quartz photomask, causing a photochemical reaction in the photoresist outside the dicing blade pattern area.

[0015] Further, the developing process described in S1 is as follows: using an alkaline developing solution with a mass fraction of 2~2.5wt%, spray developing is performed at 20±5℃ for 40~80 seconds. The alkaline developing solution includes an aqueous solution of tetramethylammonium hydroxide.

[0016] After development, the unexposed photoresist (i.e., the dicing pattern area) is completely dissolved and removed, thereby precisely exposing the metal area on substrate B that matches the shape of the final dicing product. In this process, a weakly alkaline aqueous solution with controllable concentration and stable safety is preferentially selected as the developer, which is a key chemical guarantee for achieving a photolithographic pattern accuracy of ±2μm and ensuring process reproducibility and high yield.

[0017] Furthermore, the electroplating solution used in the composite electroplating described in S2 includes nickel salt, conductive salt, buffer, wetting agent, brightener, diamond micron powder, and water; the pH value of the electroplating solution is 3.5~5.5, the electroplating temperature is 50~60℃, and the cathode current density is 2.8~3.2 A / dm³. 2 Under these conditions, by controlling the appropriate electroplating time, nickel and diamond are co-deposited within the exposed dicing blade pattern area, directly growing a composite coating of a predetermined thickness.

[0018] Further, the nickel salt includes nickel sulfamate or nickel sulfate with a concentration of 300-500 g / L; the conductive salt includes nickel chloride or nickel bromide with a concentration of 10-20 g / L; the buffer is boric acid with a concentration of 20-50 g / L; the wetting agent is sodium dodecyl sulfate with a concentration of 0.1-1 g / L; the brightener includes saccharin with a concentration of 0.5-1.5 g / L; and the diamond micron powder has a particle size of 5-10 μm and a concentration of 0.1-3 g / L.

[0019] Further, the stripping process described in S3 is as follows: the substrate D is immersed in an alkaline solution with a concentration of 90-110 g / L at 45-60°C for 5-15 minutes; the alkaline solution includes an aqueous solution of sodium hydroxide or potassium hydroxide.

[0020] Furthermore, after the alkaline solution completely hydrolyzes and dissolves the cured photoresist layer, the substrate D is removed, ultrasonically cleaned with deionized water, and dried with nitrogen. Due to the optimized bonding force between the coating and the stainless steel substrate, the formed dicing blade can be easily and completely peeled off from the substrate without any deformation.

[0021] The stripping process uses a strongly alkaline aqueous solution as the stripping solution because it is harmless to nickel-diamond plating and safe for metal substrates. Compared with organic solvent stripping solutions, water-based alkaline solutions have the advantages of low volatility, low toxicity, high safety, and easy waste treatment, making them more suitable for large-scale production.

[0022] Furthermore, the electrolyte for the electrolytic treatment in S3 includes phosphoric acid, sulfuric acid, and water, and the volume ratio of phosphoric acid, sulfuric acid, and water is 6~8:5~7:3~5.

[0023] Furthermore, the electrolytic treatment process described in S3 is as follows: using the stripped dicing blade as the anode and the titanium plate as the cathode, at 30±1℃, with an electrolytic rate of 30±5 A / dm². 2 Electrolysis is performed under current for 40-60 seconds; this process selectively removes a small amount of the nickel layer surrounding the diamond, causing the diamond particles to protrude.

[0024] The present invention further provides an electroplated scribing blade prepared using the above-described method for preparing an electroplated scribing blade.

[0025] The beneficial effects of this invention are: 1. This invention is the first to use semiconductor photolithography to electroplate and form dicing blades in a single process, replacing traditional machining and achieving a triple improvement in precision, efficiency, and quality. Its core lies in the direct forming technology using patterned masks and selective electroplating, breaking through the traditional manufacturing paradigm.

[0026] 2. The preparation method of the electroplated scribing blade provided by the present invention has a high degree of process integration and greatly improved efficiency: by replacing the traditional "electroplating + multi-pass machining" mode with "photolithography patterning + electroplating forming", complex structures can be formed by electroplating in one step, and the production cycle is shortened from several days to several hours.

[0027] 3. The preparation method of the electroplated scribing blade provided by the present invention significantly improves the processing accuracy: The present invention improves the key contour dimensions and positional accuracy (such as inner / outer diameter, groove width, roundness and coaxiality) of the scribing blade from the ±10μm level of traditional machining to the ±2μm level of photolithography patterning process, and the product consistency is fundamentally improved.

[0028] 4. The method for preparing electroplated dicing blades provided by this invention effectively improves the yield rate: Traditional dicing blade machining processes suffer from problems such as systematic dimensional drift caused by tool wear, residual stress deformation introduced by clamping and cutting, and the accumulation of errors from multiple workstations, resulting in a comprehensive scrap rate typically as high as several percentage points. This invention eliminates all subsequent machining processes, defines all features at once through photolithography, and directly forms the blade using an electroplating process without macroscopic mechanical force, thereby fundamentally eliminating all the aforementioned machining risks that lead to defective products, reducing the product defect rate by approximately half.

[0029] 5. The electroplated dicing blade provided by this invention has superior product performance: Because this invention ensures ultra-high geometric precision of the cutting edge through photolithography, and combines a composite electroplating process to achieve a uniform composite of the reinforced alloy matrix and diamond abrasive grains, the prepared dicing blade can effectively reduce impact and chipping on the workpiece during cutting. Experiments show that the chipping size can be reduced by more than 30%, and for brittle materials such as gallium arsenide, a superior effect of <3μm frontal chipping can be achieved. Attached Figure Description

[0030] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Appendix Figure 1 This is a process flow diagram of the preparation of the electroplated scribing blade in Embodiment 1 of the present invention; Appendix Figure 2 This is a schematic diagram of the electroplating scribing blade without a cooling tank prepared in Embodiment 1 of the present invention; Appendix Figure 3 This is a schematic diagram of the electroplating scribing blade with a cooling groove prepared in Embodiment 1 of the present invention. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. All mentioned embodiments are implemented based on the technical solutions of the present invention, and detailed implementation processes are given. However, it should be stated that the scope of protection of the present invention is not limited to the following embodiments.

[0033] The following embodiments provide detailed implementation procedures for the technical solutions of the present invention. Unless otherwise specified, the experimental methods used in the following experimental examples are conventional methods; unless otherwise specified, the materials and reagents used are commercially available. Example 1

[0034] Reference Figure 1The process flow shown is used to prepare a product such as Figure 2 The electroplating dicing blade shown has an outer diameter of 52 mm and an inner diameter of 40 mm.

[0035] (1) Substrate treatment: 304 stainless steel plate was selected as the substrate, with an initial surface roughness Ra of approximately 1.2. First, it was ultrasonically cleaned at 60°C for 10 minutes with 2% sodium carbonate to thoroughly remove oil, and then rinsed clean with deionized water. Subsequently, the substrate was fixed on a surface grinder and finely ground using a 1500-mesh diamond grinding wheel at a pressure of 30-100, ultimately controlling the surface roughness Ra to 0.8±0.1. After this treatment, the substrate surface achieved a mirror-like matte finish, which not only ensured the adhesion of the subsequent photoresist but also provided an ideal substrate for high-precision pattern transfer.

[0036] (2) Coating with photoresist: Place the prepared substrate on a spin coater. Select a positive photoresist (AZ) suitable for g / h / i line exposure. ® P4620). Set the spin coating parameters: first, spread the photoresist at a low speed of 500 rpm for 100 seconds, then spin coat at a high speed of 2000 rpm for 450 seconds to form a photoresist film with a thickness of approximately 100 μm. After coating, immediately transfer the substrate to a hot plate for pre-baking (soft baking) at 100°C for 2 minutes to completely remove the solvent and stabilize the photoresist film.

[0037] (3) Exposure with a photomask: A quartz photomask with a scribe blade negative image pattern (the patterned area is opaque) is used and aligned with the photoresist substrate using a contact exposure machine. A vacuum method is used to ensure tight adhesion between the photomask and the photoresist. Exposure is performed using a 1kW UV light source with an exposure dose of 150 mJ / cm². 2 UV light passes through the photomask, causing a photochemical reaction in the photoresist outside the dicing blade ring pattern area.

[0038] (4) Development: The exposed substrate is placed in a spray developer. A 2.38% tetramethylammonium hydroxide solution is used as the developer, and spray development is performed at 23°C for 60 seconds. After development, the unexposed photoresist (i.e., the dicing pattern area) is completely dissolved and removed, thereby precisely exposing a metal ring area on the substrate that matches the shape of the final product.

[0039] (5) Composite electroplating: The developed substrate is used as the cathode, and the nickel plate is used as the anode, and is vertically fixed in the electroplating tank. The composite electroplating solution is prepared with the following components: nickel sulfamate: 400 g / L, nickel chloride: 15 g / L, boric acid: 35 g / L, wetting agent (sodium dodecyl sulfate): 0.5 g / L, brightener (saccharin): 1 g / L, and synthetic diamond micro powder 4000#: 1.5 g / L.

[0040] The pH of the electroplating solution was adjusted to 4.2 using dilute sulfuric acid and heated to 55°C. Air agitation was used to uniformly suspend the diamond powder. The cathode current density was set to 3 A / dm³. 2 The power is turned on for electroplating. Under these conditions, electroplating lasts for 5 hours, during which nickel and diamond are co-deposited in the exposed annular area, directly growing a composite coating of the predetermined thickness.

[0041] (6) Photoresist Removal: After electroplating, the substrate is immersed in a 100 g / L sodium hydroxide aqueous solution at 50°C for about 10 minutes. This strong alkaline solution completely hydrolyzes and dissolves the cured photoresist layer. Subsequently, the substrate is removed, ultrasonically cleaned with deionized water, and dried with nitrogen. Due to the optimized adhesion between the plating layer and the stainless steel substrate, the formed annular dicing blade can be easily and completely peeled off from the substrate without any deformation.

[0042] (7) Electrolysis with exposed blade: Prepare the electrolyte (volume ratio HPO3:H2SO4:H2O=7:6:4, phosphoric acid concentration is 85%, sulfuric acid concentration is 98%), use the dicing blade as the anode and the titanium plate as the cathode, at 30℃ and 30A / dm 2 Electrolysis for 45 seconds under current; this step selectively removes a small amount of the nickel layer surrounding the diamond, causing the diamond particles to protrude.

[0043] (8) Inspection: Dimensional inspection and cutting tests were performed on the dicing blade. The dimensional accuracy of the inner and outer diameters of the dicing blade was improved to ±2μm, the concentricity was reduced from 50μm to within 10μm, and the product yield was improved to over 95%. Due to the improved accuracy, the dynamic runout of the dicing blade during high-speed rotary cutting was reduced, resulting in better product processing quality. When cutting a 200μm thick silicon wafer with a spindle speed of 35000rpm and a feed rate of 10mm / s, the chipping size was reduced from the original 10μm to within 5μm. Example 2

[0044] Prepare a kind of Figure 3 The electroplated dicing blade shown has 16 cooling grooves. Its preparation method differs from that of Example 1 in that: (3) Exposure with a photomask: The photomask pattern used contains all the features of the target dicing blade, namely the outer circle, the inner hole and the negative image of four uniformly distributed cooling grooves of a specific shape.

[0045] (5) Composite electroplating: The electroplating time was adjusted and set according to the complexity of the cooling tank and the required coating thickness to ensure the integrity of the structure.

[0046] Through the above adjustments, the final dicing blade achieves one-time electroplating precision forming of the outer circle, inner hole, and complex cooling tank structure, completely eliminating the traditional process of cutting the cooling tank with wire.

[0047] Comparative Example 1 The cooling groove-less dicing blade in Example 1 was prepared using conventional methods. The traditional process of "first fabricating the aluminum alloy wheel hub, then performing localized composite electroplating, and finally machining it through multiple passes" is adopted. Specifically, this includes: CNC lathe machining of the wheel hub (approximately 2.5 hours), localized electroplating (approximately 3.5 hours), external cylindrical grinding (approximately 0.8 hours), and wire EDM of the internal hole (approximately 1.2 hours). The total time for this process is approximately 7-8 hours, with a machining accuracy of approximately ±10μm and an overall yield of approximately 90%. Due to the stress introduced by machining and damage to the coating, the chipping size on the back side of the tool fluctuates significantly when cutting the silicon wafer, and the tool life is limited by the presence of microcracks.

[0048] Comparative Example 2 The dicing blade with cooling groove in Example 2 was prepared using a conventional method. The traditional process of "first manufacturing the aluminum alloy wheel hub, then performing partial composite electroplating, and finally machining it through multiple passes" is adopted. Specifically, this includes: CNC lathe machining of the wheel hub (approximately 2.5 hours), partial electroplating (approximately 3.5 hours), external cylindrical grinding (approximately 0.8 hours), wire EDM of the internal hole (approximately 1.2 hours), and the wire EDM process for creating the cooling groove adds an additional 2.5 hours, with a lower yield rate. The total production cycle is extended to 2-3 days, and due to the difficulty of creating the groove, the overall yield rate of the final product drops to approximately 85-88%. Machining damage at the cooling groove opening is more likely to cause abnormal edge chipping during cutting, affecting the consistency of cutting quality.

[0049] The electroplated scribing blades obtained in the examples and comparative examples were inspected, and the qualified products were used to cut brittle materials such as silicon wafers or gallium arsenide for verification. The test parameters are shown in Table 1 below, and the results are shown in Table 2 below.

[0050]

[0051]

[0052] As can be seen from Table 2, the dicing blade manufactured using the process of this invention has significant improvements in processing time, processing accuracy, overall yield, and cutting quality in related tests.

[0053] In summary, the "photolithography patterning + electroplating forming" method provided by this invention represents a fundamental revolution in manufacturing principles compared to the traditional "electroplating + multi-pass machining" process. Experimental data shows that this method shortens the production cycle from 3-5 days to 2-3 days, improves machining accuracy from ±10μm to ±2μm, and increases the yield of complex structure products from approximately 87% to over 95%. Simultaneously, the prepared dicing blades exhibit a reduction in cutting edge chipping size by more than 30% due to undamaged cutting edges and uniform diamond distribution. This invention achieves comprehensive and significant improvements in production efficiency, machining accuracy, product yield, and performance, providing a revolutionary solution for the manufacturing of high-end precision electroplated cutting tools.

[0054] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing an electroplated scribing blade, characterized in that, Includes the following steps: S1, a photoresist layer is formed on the pre-treated substrate A to obtain substrate B; the photoresist layer on substrate B is subjected to exposure treatment and development treatment in sequence to form a patterned window corresponding to the target shape of the dicing blade to obtain substrate C. S2, using the substrate C described in S1 as the cathode and the nickel plate as the anode; performing nickel-diamond composite electroplating in the area with the patterned window to form a coating, thus obtaining substrate D; S3, the photoresist layer on the substrate D described in S2 is removed, and the formed dicing blade is peeled off from the substrate D; the peeled dicing blade is subjected to electrolytic treatment to obtain the electroplated dicing blade.

2. The method for preparing the electroplated scribing blade as described in claim 1, characterized in that, The pretreated substrate A mentioned in S1 is a stainless steel or aluminum alloy substrate with a surface roughness Ra of 1.6 to 0.

4.

3. The method for preparing the electroplated scribing blade as described in claim 1, characterized in that, The photoresist layer described in S1 is formed by coating and then drying, and the photoresist used includes a positive photoresist suitable for UV broadband exposure.

4. The method for preparing the electroplated scribing blade as described in claim 1, characterized in that, The exposure process described in S1 is as follows: First, a quartz photomask with a dicing blade negative image pattern is bonded to substrate B, and then a UV light source with a power of 1±0.2kW is used for exposure, with an exposure dose of 140~160mJ / cm. 2 .

5. The method for preparing the electroplated scribing blade as described in claim 1, characterized in that, The developing process described in S1 is as follows: using an alkaline developing solution with a mass fraction of 2~2.5wt%, spray developing is performed at 20±5℃ for 40~80 seconds; the alkaline developing solution includes an aqueous solution of tetramethylammonium hydroxide.

6. The method for preparing the electroplated scribing blade as described in claim 1, characterized in that, The electroplating solution used in the composite electroplating described in S2 includes nickel salt, conductive salt, buffer, wetting agent, brightener, diamond micro powder and water; the pH value of the electroplating solution is 3.5~5.5, the electroplating temperature is 50~60℃, and the cathode current density is 2.8~3.2 A / dm².

7. The method for preparing the electroplated scribing blade as described in claim 6, characterized in that, The nickel salt includes nickel sulfamate or nickel sulfate, with a concentration of 300-500 g / L; the conductive salt includes nickel chloride or nickel bromide, with a concentration of 10-20 g / L; the buffer is boric acid, with a concentration of 20-50 g / L; the wetting agent is sodium dodecyl sulfate, with a concentration of 0.1-1 g / L; the brightener includes saccharin, with a concentration of 0.5-1.5 g / L; and the diamond micron powder has a particle size of 5-10 μm and a concentration of 0.1-3 g / L.

8. The method for preparing the electroplated scribing blade as described in claim 1, characterized in that, The stripping process described in S3 is as follows: the substrate D is immersed in an alkaline solution with a concentration of 90-110 g / L at 45-60°C for 5-15 minutes; the alkaline solution includes an aqueous solution of sodium hydroxide or potassium hydroxide.

9. The method for preparing the electroplated scribing blade as described in claim 1, characterized in that, The electrolyte for the electrolytic treatment described in S3 includes phosphoric acid, sulfuric acid, and water, and the volume ratio of phosphoric acid, sulfuric acid, and water is 6~8:5~7:3~5.

10. An electroplated scribing blade prepared using the preparation method of any one of claims 1 to 9.

Images