Wafer dicing method and dicing machine

Abstract

The application relates to the technical field of wafers, in particular to a wafer dicing method and a dicing machine. The wafer dicing method is used for cutting a glass-silicon bonded wafer, the glass-silicon bonded wafer comprises a silicon layer, a glass layer and a cutting protection film which are sequentially stacked; the wafer dicing method comprises installing a cutter on a main shaft of the dicing machine. The glass-silicon bonded wafer is placed on a workbench of the dicing machine, and the workbench adsorbs and fixes the cutting protection film. The dicing machine is started, and the glass-silicon bonded wafer is cut from the silicon layer according to dicing parameters. The dicing machine cuts the glass-silicon bonded wafer through the wafer dicing method, and the glass-silicon bonded wafer is cut by using a single cutter, so that the silicon layer and the glass layer are respectively cut through, and the dicing efficiency is improved. Meanwhile, the cutter cuts from the silicon layer and is cut off at the glass layer, so that the release position of the cutting stress is far away from the silicon layer, the edge collapse of the silicon layer is effectively reduced, the dicing quality is improved, and the product yield of the wafer is improved.

Description

Technical Field

[0001] This invention relates to the field of wafer technology, and more particularly to a wafer dicing method and dicing machine. Background Technology

[0002] Hundreds to thousands of chips are typically connected together on a wafer, with gaps of 80µm to 150µm between them. This gap is called the dicing area. The process of separating each chip, which has independent electrical properties, is called dicing or cutting. In the dicing process, the diamond wheel of the dicing machine cuts the dicing area of ​​the wafer at high speed, while the wafer-carrying stage moves linearly at a certain speed along the tangent direction of the blade-wafer contact point, thus realizing the wafer dicing process.

[0003] Existing glass-silicon bonded wafers are composite structures formed by bonding glass materials to silicon wafers through specific processes. This improves the hermeticity, mechanical strength, and reliability of devices while meeting the demands for miniaturization and high-performance packaging, primarily used in semiconductor packaging and sensor manufacturing. In the dicing process of glass-silicon bonded wafers, considering the differences in properties between glass and silicon, different types of cutting tools are used to cut the glass and silicon layers separately. This requires a dual-axis machine or changing the cutting tool mid-dicing, resulting in low efficiency and high cost. Using a single cutting tool to cut the glass and silicon layers sequentially results in the cutting occurring in the silicon layer, leading to excessive chipping and reduced wafer yield. Summary of the Invention

[0004] The purpose of this invention is to provide a wafer dicing method and dicing machine to improve dicing efficiency, while avoiding excessive edge chipping after glass silicon bonded wafer dicing, thereby improving product yield.

[0005] To achieve this objective, the technical solution adopted by the present invention is as follows:

[0006] A wafer dicing method for cutting glass-silicon bonded wafers, the glass-silicon bonded wafers comprising sequentially stacked silicon layers, glass layers, and a dicing protective film; the wafer dicing method includes:

[0007] Install cutting tools on the spindle of the dicing machine;

[0008] The glass-silicon bonding wafer is placed on the worktable of the dicing machine, and the worktable adsorbs and fixes the cutting protective film.

[0009] Start the dicing machine and cut the glass-silicon bonded wafer from the silicon layer according to the dicing parameters.

[0010] As an alternative method for wafer dicing, the glass-silicon bonded wafer is baked before being placed on the worktable.

[0011] As an alternative method for dicing wafers, the glass-silicon bonded wafers are baked in an oven.

[0012] As an alternative method for wafer dicing, the baking oven has a baking temperature of 80° to 90° and a baking time of 30 to 60 minutes.

[0013] As an alternative method for dicing wafers, the cutting tool is sharpened after the dicing machine is started and before the glass-silicon bonded wafer is cut.

[0014] As an alternative method for dicing wafers, in-line grinding is performed during the dicing of the glass-silicon bonded wafer.

[0015] As an alternative method for wafer dicing, after the dicing machine is started, the worktable translates along the Y-axis; the spindle is controlled so that the spindle and the cutting tool descend to the cutting position along the Z-axis, and the glass silicon bonded wafer is cut at a set rotation speed and feed rate.

[0016] As an alternative method for wafer dicing, the spindle speed is 23000 r / min and the tool feed rate is 0.5 mm / s.

[0017] A dicing machine includes a spindle, a worktable, and a cutting tool. The worktable is used to adsorb and fix glass-silicon bonded wafers. The cutting tool is mounted on the spindle and dices the glass-silicon bonded wafers using the dicing method described above.

[0018] As an alternative to the dicing machine, the dicing machine also includes a grinding plate, which is disposed on one side of the worktable and configured to grind the cutting tool.

[0019] The beneficial effects of this invention are as follows:

[0020] The wafer dicing method proposed in this invention uses a single cutter to cut glass-silicon bonded wafers, cutting through both the silicon and glass layers separately. This eliminates the need for a dual-spindle machine and cutter changes during the dicing process, improving dicing efficiency and reducing costs. Furthermore, with the silicon layer on top and the glass layer below, the cutter starts cutting from the silicon layer and cuts through the glass layer, ensuring that the stress release point is far from the silicon layer. This effectively reduces edge chipping in the silicon layer, preventing excessive chipping after dicing the glass-silicon bonded wafer, improving dicing quality, and increasing product yield.

[0021] The dicing machine proposed in this invention cuts glass-silicon bonded wafers using the above-mentioned wafer dicing method, effectively reducing edge chipping of the silicon layer, avoiding excessive edge chipping after cutting the glass-silicon bonded wafers, improving dicing quality, and increasing product yield. Attached Figure Description

[0022] Figure 1 This is a partial structural schematic diagram of a dicing machine cutting glass-silicon bonded wafers according to an embodiment of the present invention;

[0023] Figure 2 This is a main flowchart of the wafer dicing method provided in the embodiments of the present invention;

[0024] Figure 3 This is a front view of the glass-silicon bonded wafer after dicing, as provided in an embodiment of the present invention.

[0025] The component names and labels in the diagram are as follows:

[0026] 100. Glass-silicon bonded wafer; 10. Silicon layer; 20. Glass layer; 30. Cutting protective film;

[0027] 1. Spindle; 11. Hub; 12. Flange; 2. Worktable; 3. Cutting tool. Detailed Implementation

[0028] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. Furthermore, it should be noted that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, not all of them.

[0029] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] In the description of this embodiment, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0032] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 1 As shown, this embodiment proposes a dicing machine, which includes a spindle 1, a worktable 2, and a cutting tool 3. The worktable 2 is used to adsorb and fix a glass-silicon bonded wafer 100, and the cutting tool 3 is mounted on the spindle 1 to cut the glass-silicon bonded wafer 100. Specifically, the output end of the spindle 1 has a hub 11, and the cutting tool 3 is mounted on the hub 11 and fixedly assembled with the hub 11 through a flange 12 so that the cutting tool 3 and the hub 11 rotate synchronously. Of course, this dicing machine can also cut other types of wafers, which are not specifically limited here.

[0034] Specifically, the glass-silicon bonded wafer 100 includes a silicon layer 10, a glass layer 20, and a dicing protective film 30 stacked sequentially. In this embodiment, the dicing protective film 30 is a UV blue film. The UV blue film has strong adhesion and can be firmly fixed on the worktable 2 to prevent the glass-silicon bonded wafer 100 from shifting or rotating during the dicing process, thus ensuring dicing accuracy and consistency. At the same time, the UV blue film can also reduce the impact of heat generated during the dicing process on the glass-silicon bonded wafer 100, further improving the dicing quality.

[0035] In existing dicing processes, considering the differences in properties between glass and silicon, different types of cutting tools 3 are used to cut the glass layer 20 and silicon layer 10 respectively. This requires a dual-axis machine or changing the cutting tool midway through dicing, resulting in low efficiency and high cost. Furthermore, using a single cutting tool 3 to cut the glass layer 20 and silicon layer 10 sequentially causes the cutting point to occur on the silicon layer 10, leading to excessive chipping and reduced wafer yield.

[0036] To solve the above problems, such as Figure 1 and Figure 2 As shown, this embodiment also discloses a wafer dicing method, in which a dicing machine dices a glass-silicon bonded wafer 100. The wafer dicing method includes:

[0037] Install the cutting tool 3 on the spindle 1 of the dicing machine.

[0038] The glass-silicon bonded wafer 100 is placed on the worktable 2 of the dicing machine, and the worktable 2 adsorbs and fixes the cutting protective film 30.

[0039] Start the dicing machine and cut the glass-silicon bonded wafer 100 starting from silicon layer 10 according to the dicing parameters.

[0040] By using a single cutter 3 to dice the glass-silicon bonded wafer 100, both the silicon layer 10 and the glass layer 20 are cut through. This eliminates the need for a dual-spindle machine and the need to change the cutter 3 during the dicing process, improving dicing efficiency and reducing dicing costs. Furthermore, with the silicon layer 10 on top and the glass layer 20 below, the cutter 3 starts cutting from the silicon layer 10 and cuts off at the glass layer 20. This ensures that the stress release point is far from the silicon layer 10, effectively reducing edge chipping of the silicon layer 10 and preventing excessive edge chipping after dicing the glass-silicon bonded wafer 100. This improves dicing quality and increases product yield.

[0041] like Figure 3 As shown, the cutter 3 needs to cut part of the protective film 30 during cutting to ensure that it can completely cut through the glass layer 20.

[0042] It should be noted that the glass-silicon bonded wafer 100 is baked before being placed on the worktable 2. The baking operation increases the bonding strength between the dicing protective film 30 and the glass layer 20, improves the structural stability of the glass-silicon bonded wafer 100, and thus prevents the glass-silicon bonded wafer 100 from shifting or rotating during the dicing process.

[0043] Specifically, the glass-silicon bonded wafer 100 is baked in an oven. Using an oven for baking the glass-silicon bonded wafer 100 results in lower costs. Furthermore, multiple glass-silicon bonded wafers 100 can be baked simultaneously, further improving baking efficiency and reducing costs. In this embodiment, the baking temperature of the oven is 80°C–90°C, and the baking time is 30–60 minutes. The baking temperature can be 80°C, 82°C, 84°C, 86°C, 88°C, or 90°C, and the baking time can be 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, or 60 minutes, etc. These settings achieve both baking efficiency and baking quality. If the baking temperature is too low and / or the baking time is too short, the baking quality is reduced, potentially leading to a negligible increase in the viscosity of the cutting protective film 30; if the baking temperature is too high, it can damage the cutting protective film 30; if the baking time is too long, the baking efficiency is reduced.

[0044] In this embodiment, the cutting tool 3 is sharpened after starting the dicing machine and before cutting the glass-silicon bonded wafer 100. The main component of the cutting tool 3 involved in the dicing process is diamond, and the binder primarily serves to bond the diamond. Sharpening the tool before dicing fully exposes the diamond particles in the cutting tool 3, increasing its cutting force and preventing serpentine deformation that could lead to tool breakage. This improves the safety of the cutting tool 3 and the dicing quality during the dicing process.

[0045] Furthermore, during the dicing of the glass-silicon bonded wafer 100, in-line grinding is performed. This in-line grinding refers to grinding the tool 3 immediately after it has cut the glass-silicon bonded wafer 100 for a certain time or number of times (the time and number of times can be flexibly set), and then continuing with the dicing process. By setting an in-line grinding step, the tool 3 maintains a stable cutting force throughout the dicing process, avoiding the problem of the tool 3 breaking in a serpentine pattern due to a decrease in cutting force.

[0046] Specifically, the dicing machine also includes a grinding plate, which is disposed on one side of the worktable 2 and configured to grind the cutting tool 3. By setting up the grinding plate, the cutting tool 3 can be ground online during the cutting process, thus improving the problem of reduced cutting force of the cutting tool 3.

[0047] In this embodiment, after the dicing machine is started, the worktable 2 translates along the Y-axis. The spindle 1 is controlled to descend along the Z-axis to the cutting position with the cutter 3, and cuts the glass-silicon bonding wafer 100 at the set rotational speed and feed rate. The Z-axis is the height direction, the X-axis is parallel to the axis of the spindle 1, and the X-axis, Y-axis, and Z-axis are perpendicular to each other. Since the dicing process of the dicing machine is existing technology, the specific dicing steps of the dicing machine will not be described in detail.

[0048] Specifically, in this embodiment, the spindle speed 1 is 23000 r / min, and the feed rate of the tool 3 is 0.5 mm / s. The selected tool 3 is model SD800, where the number 800 indicates the particle size of the diamond particles in the tool 3. According to the characteristics of the grinding mechanism, the larger the diamond particle size, the greater the impact force on the glass-silicon bonded wafer 100, resulting in a larger chipping size of the glass-silicon bonded wafer 100. By selecting the SD800 tool 3, the diamond particle size in the tool 3 is kept within a suitable range, reducing chipping while ensuring that the tool 3 has sufficient cutting force, so that the tool 3 has high adaptability and dicing effect.

[0049] The above embodiments merely illustrate the basic principles and characteristics of the present invention. The present invention is not limited to the above embodiments. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A wafer dicing method for dicing glass-silicon bonded wafers (100), the glass-silicon bonded wafers (100) comprising a silicon layer (10), a glass layer (20), and a dicing protective film (30) stacked sequentially; characterized in that, The wafer dicing method includes: Install the cutting tool (3) on the spindle (1) of the dicing machine; The glass-silicon bonded wafer (100) is placed on the worktable (2) of the dicing machine, and the worktable (2) adsorbs and fixes the cutting protective film (30). Start the dicing machine and cut the glass silicon bonded wafer (100) from the silicon layer (10) according to the dicing parameters. The cutter (3) cuts part of the cutting protective film (30) during the cutting process.

2. The wafer dicing method according to claim 1, characterized in that, Before the glass-silicon bonded wafer (100) is placed on the worktable (2), the glass-silicon bonded wafer (100) is baked.

3. The wafer dicing method according to claim 2, characterized in that, The glass-silicon bonded wafer (100) is baked in an oven.

4. The wafer dicing method according to claim 3, characterized in that, The baking temperature of the oven is 80° to 90°, and the baking time is 30 to 60 minutes.

5. The wafer dicing method according to claim 1, characterized in that, The cutting tool (3) is sharpened after the dicing machine is started and before the glass silicon bonded wafer (100) is cut.

6. The wafer dicing method according to claim 5, characterized in that, During the cutting of the glass-silicon bonded wafer (100), in-line grinding is performed.

7. The wafer dicing method according to claim 6, characterized in that, After the dicing machine is started, the worktable (2) moves along the Y-axis; the spindle (1) is controlled so that the spindle (1) and the cutting tool (3) descend to the cutting position along the Z-axis and cut the glass silicon bonded wafer (100) at the set rotation speed and feed rate.

8. The wafer dicing method according to claim 7, characterized in that, The spindle (1) rotates at 23,000 r / min and the tool (3) feeds at 0.5 mm / s.

9. A dicing machine, characterized in that, The device includes a spindle (1), a worktable (2), and a cutting tool (3). The worktable (2) is used to adsorb and fix the glass silicon bonded wafer (100). The cutting tool (3) is mounted on the spindle (1) and the glass silicon bonded wafer (100) is diced by the wafer dicing method according to any one of claims 1 to 8.

10. The dicing machine according to claim 9, characterized in that, The dicing machine also includes a grinding plate, which is disposed on one side of the worktable (2) and configured to grind the cutting tool (3).

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