A dicing blade pre-cut plate and a preparation method and application thereof

Abstract

The present application belongs to abrasive tool technology, and particularly relates to a pre-cut plate for scribing blade, and a preparation method and application thereof. The scribing blade ground by the pre-cut plate can make the cutting trace smaller than before grinding, and the chipping no longer appears. The abrasive with mixed particle size and the compounded resin binder are used to grind the hard blade with fine particle size (3000#-5000#). The highest feeding rate that can be sustained during grinding the hard blade with fine particle size by the pre-cut plate is increased from 10 mm / s to 80 mm / s, and 10 blades can be ground, which greatly improves the efficiency compared with the traditional grinding of 200 blades. After grinding the blade, the feeding rate for scribing the silicon wafer can be increased from 5 mm / s to 70 mm / s. The cutting trace of the silicon wafer after grinding the blade is 3-4 um smaller than the existing grinding blade, and the front and back chipping no longer appears, which greatly saves the grinding time, improves the efficiency, improves the utilization rate of the silicon wafer, and saves the cost.

Description

Technical Field

[0001] This invention belongs to the field of abrasive technology, specifically relating to a dicing blade pre-cutting plate and its preparation method and application. The dicing blade ground by this invention can cut silicon wafers, making the cutting path smaller than before grinding, and eliminating chipping. Background Technology

[0002] Currently, the substrate material for integrated circuits is mainly single-crystal silicon wafers. After the circuitry is densely packed onto the silicon wafer, it needs to be cut and separated into individual wafers along the dicing grooves using a dicing blade. This process is called "dicing." Current dicing tools are mainly hub-type diamond blades, which are electroplated and called hard blades. Before and during use, hard blades need to be sharpened to expose the diamond and form "pockets" for optimal performance. The tool used for sharpening these blades is called a pre-cutting board. Currently, with the increasing demand for high silicon wafer utilization and heat dissipation, the dicing grooves on silicon wafers are becoming narrower. Furthermore, silicon wafers diced with hard blades must be free from front-side chipping, back-side chipping, and wide dicing grooves. This places higher demands on the pre-cutting board. Existing pre-cutting boards produce dicing blades with wide dicing grooves and chipping issues. Summary of the Invention

[0003] This invention relates to a pre-cutting plate. Through a unique formula design, the pre-cutting plate achieves a uniform structure and moderate strength. Utilizing a mixed-size abrasive and a compounded resin binder, it can grind fine-grained (3000#-5000#) hard blades. Using this pre-cutting plate, the maximum feed rate that can be tolerated during grinding is increased from 10mm / s to 80mm / s, requiring only 10 grinds. This significantly improves efficiency compared to the traditional method of grinding silicon wafers with 200 grinds. After grinding, the silicon wafer feed rate can be increased from 5mm / s to 70mm / s. The kerf after grinding is 3-4μm smaller than existing grinding methods, eliminating front and back chipping. This greatly saves grinding time and improves efficiency, increasing silicon wafer utilization and reducing costs.

[0004] The present invention adopts the following technical solution: A dicing blade pre-cutting plate is obtained by hot pressing a mixture of silicon carbide of mixed particle size and a compound resin powder.

[0005] This invention discloses a method for preparing the aforementioned dicing blade pre-cutting plate, comprising the following steps: weighing silicon carbide powder and compound resin powder of mixed particle size, mixing them, adding them to a mold, and hot-pressing to obtain the dicing blade pre-cutting plate. Specifically, weighing silicon carbide powder and compound resin powder of mixed particle size, and ball-milling them; adding the mixed material to a mold, hot-pressing to form; and then performing conventional machining to obtain the dicing blade pre-cutting plate.

[0006] In this invention, the mixed-size silicon carbide powder is obtained by mixing silicon carbide powder with a particle size of W2.5 and silicon carbide powder with a particle size of W2. Preferably, the mass ratio of silicon carbide powder with a particle size of W2.5 to silicon carbide powder with a particle size of W2 is (2-5):(8-5), and more preferably, the mass ratio of silicon carbide powder with a particle size of W2.5 to silicon carbide powder with a particle size of W2 is (2-4):(8-6), for example, 3:7.

[0007] In this invention, the compound resin powder is a mixture of phenolic resin powder and epoxy resin powder. Preferably, the mass percentage of phenolic resin powder in the compound resin powder is 60-80%, and more preferably 65-75%.

[0008] In this invention, the mass ratio of silicon carbide powder to composite resin powder is (4-6):(4-6), preferably, the mass ratio of silicon carbide powder to composite resin powder is 4:6.

[0009] This invention discloses the application of the above-mentioned dicing blade pre-cutting plate in the machining of diamond blades for wheel hubs.

[0010] This invention discloses the application of the above-mentioned dicing blade pre-cutting plate in the processing of silicon wafer cutting blades.

[0011] This invention discloses a method for sharpening wheel hub diamond cutting tools, comprising the following steps: using the aforementioned dicing blade pre-cutting plate to sharpen wheel hub diamond cutting tools, thereby achieving the sharpening of wheel hub diamond cutting tools.

[0012] This invention discloses a method for cutting silicon wafers, comprising the following steps: using the aforementioned dicing blade pre-cutting plate to grind a hub diamond blade, and then using the ground hub diamond blade to cut the silicon wafer.

[0013] Existing technologies use silicon carbide, graphite, and resin powder as raw materials to prepare grinding plates, which can reduce the number of grinding cycles. However, when cutting silicon wafers with these materials, problems such as front-side chipping, back-side chipping, and wide kerf widths have been found. This invention adjusts the formula, omitting graphite, and uses a mixture of silicon carbide with mixed particle sizes and a compound resin powder, followed by hot pressing, to obtain a new type of dicing blade pre-cutting plate. This reduces the number of grinding cycles and the kerf width simultaneously. Unexpectedly, no front-side or back-side chipping occurred during the dicing blade's service life. This significantly saves grinding time, improves efficiency, increases silicon wafer utilization, and reduces costs. Attached Figure Description

[0014] Figure 1 This is a cross-sectional electron microscope image of the pre-cut plate in Example 1.

[0015] Figure 2 The dicing marks for cutting silicon wafers with an unground dicing blade.

[0016] Figure 3 Chipping on the back side of a silicon wafer cut with an unground dicing blade.

[0017] Figure 4 In Example 1, after the pre-cutting board is ground, the dicing blade cuts the dicing path of the silicon wafer.

[0018] Figure 5 In Example 1, after the pre-cutting board was ground, the back side of the silicon wafer cut by the dicing blade was free of chipping. Detailed Implementation

[0019] This invention relates to a pre-cutting plate. Through a unique formulation design, the pre-cutting plate exhibits a uniform structure, a porosity of approximately 11%, and moderate strength. Utilizing a mixed-size abrasive and a compounded resin binder, it can grind fine-grained (3000#-5000#) hard blades. Using this pre-cutting plate, the maximum feed rate during grinding is increased from 10mm / s to 80mm / s, requiring only 10 passes. This significantly improves efficiency compared to the traditional method of grinding silicon wafers with 200 passes. After grinding, the silicon wafer feed rate can be increased from 5mm / s to 70mm / s. The kerf after grinding is 3-4μm smaller than existing grinding methods, eliminating front and back chipping. This greatly saves grinding time and improves efficiency, increasing silicon wafer utilization and reducing costs.

[0020] The dicing blade pre-cutting plate of the present invention is obtained by hot pressing a mixture of silicon carbide and compound resin powder of mixed particle size. Specifically, silicon carbide powder and compound resin powder of mixed particle size are weighed and ball-milled; the mixed material is added into a mold and hot-pressed; and then conventional machining is performed to obtain the dicing blade pre-cutting plate.

[0021] In this invention, the mixed-size silicon carbide powder is obtained by mixing silicon carbide powder with a particle size of W2.5 and silicon carbide powder with a particle size of W2. Preferably, the mass ratio of silicon carbide powder with a particle size of W2.5 to silicon carbide powder with a particle size of W2 is (2-5):(8-5), and more preferably, the mass ratio of silicon carbide powder with a particle size of W2.5 to silicon carbide powder with a particle size of W2 is (2-4):(8-6), for example, 3:7.

[0022] In this invention, the compound resin powder is a mixture of phenolic resin powder and epoxy resin powder. Preferably, the mass percentage of phenolic resin powder in the compound resin powder is 60-80%, and more preferably 65-75%.

[0023] In this invention, the mass ratio of silicon carbide powder to composite resin powder is (4-6):(4-6), preferably, the mass ratio of silicon carbide powder to composite resin powder is 4:6.

[0024] In this invention, ball milling, molding and hot pressing, and machining are all conventional methods. For example, hot pressing is carried out at 170°C for 60 minutes and at a pressure of 70 MPa.

[0025] The following experiments illustrate the technological advancements of this invention. The specific raw materials are all existing products that meet the relevant requirements for abrasives. The resin can be purchased from Shengquan Chemical. The specific preparation operations and performance tests are existing technologies. The hot pressing is carried out at 170°C for 60 minutes at a pressure of 70MPa. Conventional machining involves grinding the upper and lower surfaces of the grinding plate using a grinding machine. Example 1

[0026] Weigh 120g of silicon carbide powder (W2.5), 280g of silicon carbide powder (W2), 420g of phenolic resin powder, and 180g of epoxy resin powder, and mix them in a ball mill (300rpm) for 1 hour; add the mixed material into a mold and hot press it into shape; then perform conventional machining to obtain a dicing blade pre-cut plate. Figure 1 This is a cross-sectional electron microscope image of the pre-cut plate. The porosity is approximately 11%.

[0027] Comparison Example The existing hub-type nickel-based dicing blade grinding plate is a product already available to the applicant, and the preparation method is described in Example 4 of CN115990842A.

[0028] Application Examples

[0029] The hub-type dicing blade model is S200-4000#-C-BH6-2652, which is an existing product and is prepared by electroplating.

[0030] Example 1: Grinding process for pre-cut plate: feed 80mm / s; cutting depth 0.3mm; number of grinding blades: 10; spindle speed: 30000rpm.

[0031] The grinding process of the comparative grinding plate is as follows: feed: 10mm / s; depth of cut: 0.3mm; number of grinding cuts: 16; spindle speed: 30000rpm.

[0032] Cutting experiments were conducted using a hub-type dicing blade of the same specification, after being sharpened in Example 1 and the control example respectively: cutting 0.3mm silicon wafers; cutting depth: cutting through the material; spindle speed: 30000rpm. The hub-type dicing blade before sharpening served as a blank control.

[0033] Before sharpening, the feed rate of the hub-type dicing cutter was 5mm / s, resulting in a relatively wide cutting path. Figure 2 The dicing groove for cutting a silicon wafer with an unground dicing blade is 26.778 μm. Figure 3 The back side of the silicon wafer cut by an unground dicing blade has chipping.

[0034] The tool used in Example 1 was ground with a feed rate of 70 mm / s. Figure 4 The dicing groove for the silicon wafer is 22.459 μm, created by the pre-cutting board grinding tool in Example 1. Figure 5In Example 1, after the pre-cutting board was ground, the dicing blade cut the back side of the silicon wafer without chipping.

[0035] Compared to the example of sharpening a knife, the feed rate is 10mm / s; and a wide cut occurs, meaning the width of the cutting path is wider than the original blade thickness (before sharpening).

[0036] As can be seen, after sharpening in Example 1, the maximum width is less than 25μm within the cutting lifespan. However, after sharpening with existing sharpening boards, the maximum width is greater than 25μm within the cutting lifespan, exceeding the width of the dicing blade before sharpening, which does not meet the customer's requirement of a silicon wafer dicing width of less than 25μm. In particular, the dicing path of the silicon wafer cut by the pre-cutting board sharpening tool of this invention is 3-4μm smaller than before sharpening, eliminating front and back chipping. This invention solves the problem of front and back chipping occurring during the cutting lifespan of silicon wafers cut with existing sharpening boards.

[0037] In addition, the present invention achieves a technological advancement of 10 grinding cycles compared to the existing grinding plates which require 16 grinding cycles. It also increases the feed rate, greatly saves grinding time, and improves efficiency; it also increases the utilization rate of silicon wafers and saves costs.

[0038] No matter how well the imported grinding plates currently available on the market are ground, they cannot fully meet the requirements of a cleavage width of less than 25μm (and the cleavage width will be wider than that of an unground blade) when cutting 0.3mm silicon wafers, and they will not cause chipping on the front or back sides.

[0039] Comparative Example 1 Weigh 400g of silicon carbide powder (W2.5), 420g of phenolic resin powder, and 180g of epoxy resin powder, and mix them in a ball mill (300rpm) for 1 hour; add the mixed material into a mold and hot press it into shape; then perform conventional machining to obtain a dicing blade pre-cut plate.

[0040] Weigh 400g of silicon carbide powder (W2), 420g of phenolic resin powder, and 180g of epoxy resin powder, and mix them in a ball mill (300rpm) for 1 hour; add the mixed material into a mold and hot press it into shape; then perform conventional machining to obtain a dicing blade pre-cut plate.

[0041] Comparative Example 2 Weigh 120g of silicon carbide powder (W2.5), 280g of silicon carbide powder (W2), and 600g of phenolic resin powder, and mix them in a ball mill (300rpm) for 1 hour; add the mixed material into a mold and hot press it into shape; then perform conventional machining to obtain a dicing blade pre-cut plate.

[0042] Comparative Example 3 Weigh 90g of silicon carbide powder (W2.5), 210g of silicon carbide powder (W2), 100g of graphite powder, 420g of phenolic resin powder, and 180g of epoxy resin powder, and mix them in a ball mill (300rpm) for 1 hour; add the mixed material into a mold and hot press it into shape; then perform conventional machining to obtain a dicing blade pre-cut plate.

[0043] Parallel experiments of the application examples were conducted using pre-cut plates of the comparative examples, and it was found that wide cuts occurred in all of them; moreover, chipping occurred in comparative example 1. Example 2

[0044] Weigh 130g of silicon carbide powder (W2.5), 280g of silicon carbide powder (W2), 420g of phenolic resin powder, and 170g of epoxy resin powder, and mix them in a ball mill (500rpm) for 2 hours; add the mixed material into a mold and hot press it into shape; then perform conventional machining to obtain a dicing blade pre-cut plate. Example 3

[0045] Weigh 120g of silicon carbide powder (W2.5), 250g of silicon carbide powder (W2), 440g of phenolic resin powder, and 190g of epoxy resin powder, and mix them in a ball mill (300rpm) for 1.5 hours; add the mixed material into a mold and hot press it into shape; then perform conventional machining to obtain a dicing blade pre-cut plate.

[0046] The applicant previously disclosed a grinding plate made of silicon carbide powder, phenolic resin, and graphite, which could reduce the number of grinding passes. However, some problems arose during actual use, mainly due to stricter customer requirements. Crucially, the silicon wafers after dicing must be free of front and back chipping, and the dicing kerf must be less than 25μm. The dicing blades ground by this grinding plate failed to meet these requirements within their service life. This invention upgrades the formula of the previously disclosed grinding plate, reducing the number of grinding passes, increasing the feed rate, and narrowing the dicing kerf after cutting the silicon wafer. This significantly improves grinding efficiency and silicon wafer utilization.

Claims

1. A dicing blade pre-cutting plate, characterized in that, It is obtained by hot pressing a mixture of silicon carbide powder of mixed particle size and a compound resin powder; the silicon carbide powder of mixed particle size is obtained by mixing silicon carbide powder of particle size W2.5 and silicon carbide powder of particle size W2; the compound resin powder is a mixture of phenolic resin powder and epoxy resin powder; the mass ratio of silicon carbide powder of particle size W2.5 to silicon carbide powder of particle size W2 is (2-5):(8-5); in the compound resin powder, the mass percentage of phenolic resin powder is 60-80%; the mass ratio of silicon carbide powder to compound resin powder is (4-6):(4-6).

2. The method for preparing the dicing blade pre-cutting plate according to claim 1, characterized in that, The process includes the following steps: weighing silicon carbide powder and compound resin powder of mixed particle size, mixing them, adding them to a mold, and hot pressing them to form a dicing blade pre-cut plate.

3. The application of the dicing blade pre-cutting plate according to claim 1 in the machining of diamond blades for wheel hubs.

4. The application of the dicing blade pre-cutting plate according to claim 1 in the processing of silicon wafer cutting blades.

5. A method for sharpening a wheel hub diamond cutting tool, comprising the following steps: using the dicing blade pre-cutting plate as described in claim 1 to sharpen the wheel hub diamond cutting tool, thereby achieving the sharpening of the wheel hub diamond cutting tool.

6. A method for cutting silicon wafers, characterized in that, The process includes the following steps: using the dicing blade pre-cutting plate described in claim 1 to grind a hub diamond blade, and then using the ground hub diamond blade to cut silicon wafers.

Images