Scribing method of wafer and scribing machine

Abstract

The invention relates to the technical field of wafers, in particular to a wafer scribing method and a scribing machine. The wafer scribing method is used for cutting a glass-silicon bonded wafer, and the glass-silicon bonded wafer comprises a silicon layer, a glass layer and a cutting protective film which are sequentially stacked. A method of scribing a wafer includes mounting a cutter on a spindle of a scriber. The glass silicon bonding wafer is placed on a workbench of the scribing machine, and the workbench adsorbs, fixes and cuts the protective film. And starting the scribing machine, and cutting the glass silicon bonded wafer from the silicon layer according to the scribing parameters. The scribing machine cuts the glass-silicon bonded wafer through the scribing method of the wafer, and cuts the glass-silicon bonded wafer through a single cutter so as to respectively cut through a silicon layer and a glass layer, so that the scribing efficiency is improved. Meanwhile, the cutter begins to cut from the silicon layer and cuts off the glass layer, so that the release position of the cutting stress is far away from the silicon layer, the edge breakage of the silicon layer is effectively reduced, the scribing quality is improved, and the product yield of wafers is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wafers, and particularly to a wafer dicing method and a dicing machine. Background Art

[0002] There are usually hundreds to thousands of chips connected together on a wafer, with a gap of 80um to 150um left between them. This gap is called the dicing area, and the process of separating each chip with independent electrical performance is called dicing or cutting. In the dicing process, the diamond grinding wheel tool of the dicing machine cuts the dicing area of the wafer at a high speed, and at the same time, the workbench carrying the wafer moves linearly along the tangent direction of the contact point between the blade and the wafer at a certain speed to realize the dicing process of the wafer.

[0003] The existing glass-silicon bonded wafer is a composite structure formed by bonding a glass material and a silicon wafer through a specific process to improve the airtightness, mechanical strength and reliability of the device, while meeting the packaging requirements of miniaturization and high performance, and is mainly used in the fields of semiconductor packaging and sensor manufacturing. In the dicing process of the glass-silicon bonded wafer, considering the different characteristics of the glass and silicon materials, different types of tools are used to cut the glass layer and the silicon layer respectively during cutting, and a dual-axis machine tool or a blade needs to be replaced during dicing, resulting in low efficiency and high cost. When using a single tool to cut the glass layer and the silicon layer in sequence, the cutting position occurs in the silicon layer, resulting in an excessive chipping range and reducing the product yield of the wafer. Summary of the Invention

[0004] The purpose of the present invention is to provide a wafer dicing method and a dicing machine to improve the dicing efficiency, avoid excessive chipping after cutting the glass-silicon bonded wafer, and improve the product yield.

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

[0006] A wafer dicing method for cutting a glass-silicon bonded wafer, the glass-silicon bonded wafer including a silicon layer, a glass layer and a cutting protective film stacked in sequence; the wafer dicing method includes:

[0007] Install a tool on the main shaft of the dicing machine;

[0008] Place the glass-silicon bonded wafer on the workbench of the dicing machine, and the workbench adsorbs and fixes the cutting protective film;

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

[0010] As an optional solution of the wafer dicing method, before placing the glass-silicon bonded wafer on the workbench, bake the glass-silicon bonded wafer.

[0011] As an alternative to the method of dicing the wafer, bake the glass-silicon bonded wafer in an oven.

[0012] As an alternative to the method of dicing the wafer, the baking temperature of the oven is 80°-90°, and the baking time is 30 min - 60 min.

[0013] As an alternative to the method of dicing the wafer, grind the cutting tool after starting the dicing machine and before cutting the glass-silicon bonded wafer.

[0014] As an alternative to the method of dicing the wafer, perform on-line tool grinding during the process of cutting the glass-silicon bonded wafer.

[0015] As an alternative to the method of dicing the wafer, after starting the dicing machine, the workbench translates along the Y-axis; control the main shaft so that the main shaft and the cutting tool descend along the Z-axis direction to the cutting position, and cut the glass-silicon bonded wafer at a set rotational speed and feed rate.

[0016] As an alternative to the method of dicing the wafer, the rotational speed of the main shaft is 23000 r / min, and the feed rate of the cutting tool is 0.5 mm / s.

[0017] A dicing machine, comprising a main shaft, a workbench and a cutting tool, the workbench is used for adsorbing and fixing a glass-silicon bonded wafer, the cutting tool is installed on the main shaft, and the glass-silicon bonded wafer is diced by the above method of dicing the wafer.

[0018] As an alternative to the dicing machine, the dicing machine further comprises a tool grinding plate, the tool grinding plate is arranged on one side of the workbench and is configured to grind the cutting tool.

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

[0020] The method of dicing the wafer proposed by the present invention cuts the glass-silicon bonded wafer with a single cutting tool to cut through the silicon layer and the glass layer respectively, without using a double-spindle machine and without replacing the cutting tool during the dicing process, improving the dicing efficiency and reducing the dicing cost. At the same time, the silicon layer is on top and the glass layer is at the bottom, and the cutting tool starts cutting from the silicon layer and cuts off at the glass layer, so that the release position of the cutting stress is far from the silicon layer, effectively reducing the chipping of the silicon layer, avoiding excessive chipping range after cutting the glass-silicon bonded wafer, improving the dicing quality and increasing the product yield.

[0021] The dicing machine proposed by the present invention cuts the glass-silicon bonded wafer by the above method of dicing the wafer, effectively reducing the chipping of the silicon layer, avoiding excessive chipping range after cutting the glass-silicon bonded wafer, improving the dicing quality and increasing the product yield. Description of the Drawings

[0022] Figure 1 It is a partial structural schematic diagram of a glass-silicon bonded wafer cut by a dicing machine provided by an embodiment of the present invention;

[0023] Figure 2 It is a main flow chart of a wafer dicing method provided by an embodiment of the present invention;

[0024] Figure 3 It is a front view of a glass-silicon bonded wafer after cutting provided by an embodiment of the present invention.

[0025] The names and reference numerals of the components in the figure are as follows:

[0026] 100, glass-silicon bonded wafer; 10, silicon layer; 20, glass layer; 30, cutting protective film;

[0027] 1, main shaft; 11, hub; 12, flange; 2, workbench; 3, cutting tool. Specific Embodiments

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

[0029] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "below", "under", and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0031] In the description of this embodiment, the orientation or positional relationships such as "upper", "lower", "right", "left", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operations, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meanings.

[0032] The technical solution of the present invention will be further described below in conjunction with the drawings and through specific embodiments.

[0033] As Figure 1 shown, this embodiment provides a dicing machine, which includes a main shaft 1, a workbench 2 and a cutting tool 3. The workbench 2 is used to adsorb and fix the glass-silicon bonded wafer 100. The cutting tool 3 is installed on the main shaft 1 to cut the glass-silicon bonded wafer 100. Specifically, the output end of the main shaft 1 has a hub 11, and the cutting tool 3 is installed on the hub 11 and fixedly assembled with the hub 11 through a flange 12, so that the cutting tool 3 rotates synchronously with the hub 11. Of course, this dicing machine can also cut other types of wafers, which will not be specifically limited herein.

[0034] Specifically, the glass-silicon bonded wafer 100 includes a silicon layer 10, a glass layer 20 and a cutting protective film 30 stacked in sequence. The cutting protective film 30 in this embodiment is a UV blue film, which has strong adhesiveness and can be firmly fixed on the workbench 2 to prevent the glass-silicon bonded wafer 100 from shifting or rotating during the dicing process, so as to ensure the dicing accuracy and consistency. At the same time, the UV blue film can also reduce the influence of the heat generated during the dicing process on the glass-silicon bonded wafer 100, and further improve the dicing quality.

[0035] In the existing dicing process, considering the different characteristics of glass and silicon materials, different types of cutting tools 3 are used to cut the glass layer 20 and the silicon layer 10 respectively during cutting, and a dual-axis machine tool or a blade needs to be replaced halfway during dicing, resulting in low efficiency and high cost. When using a single cutting tool 3 to cut the glass layer 20 and the silicon layer 10 in sequence, the cutting-off position occurs in the silicon layer 10, resulting in an excessive chipping range and reducing the product yield of the wafer.

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

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

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

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

[0040] By using a single tool 3 to cut the glass-silicon bonded wafer 100 to cut through the silicon layer 10 and the glass layer 20 respectively, there is no need to use a double-spindle 1 machine tool and there is no need to replace the tool 3 during the dicing process, which improves the dicing efficiency and reduces the dicing cost. At the same time, with the silicon layer 10 on top and the glass layer 20 at the bottom, the tool 3 starts cutting from the silicon layer 10 and cuts off at the glass layer 20, so that the release position of the cutting stress is far from the silicon layer 10, effectively reducing the chipping of the silicon layer 10 and avoiding excessive chipping range after cutting the glass-silicon bonded wafer 100, improving the dicing quality and increasing the product yield.

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

[0042] It should be noted that before the glass-silicon bonded wafer 100 is placed on the workbench 2, the glass-silicon bonded wafer 100 is baked. Through the baking operation, the bonding strength between the cutting protective film 30 and the glass layer 20 can be increased, and the structural stability of the glass-silicon bonded wafer 100 can be improved, thereby preventing 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. By using the oven for the baking process of the glass-silicon bonded wafer 100, the cost is relatively low. Moreover, multiple glass-silicon bonded wafers 100 can be baked simultaneously, further improving the baking efficiency and reducing the baking cost. The baking temperature of the oven in this embodiment is 80° - 90°, and the baking time is 30 min - 60 min. The baking temperature can be 80°, 82°, 84°, 86°, 88° or 90°, etc., and the baking time can be 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min, etc. Through the above settings, both baking efficiency and baking quality can be achieved. If the baking temperature is too low and / or the baking time is too short, the baking quality is reduced, and it is easy to cause the viscosity of the cutting protective film 30 to increase insignificantly; if the baking temperature is too high, it is easy to damage the cutting protective film 30; if the baking time is too long, the baking efficiency is reduced.

[0044] In this embodiment, the tool 3 is sharpened after the dicing machine is started and before the glass-silicon bonded wafer 100 is cut. The diamond is the main component in the tool 3 that participates in the dicing process, and the binder mainly serves to bond the diamond. By sharpening the tool before dicing, the diamond particles in the tool 3 can be fully exposed, improving the cutting force of the tool 3 and avoiding the snake-shaped deformation of the tool 3 resulting in snake-shaped tool breakage, thereby improving the safety of the tool 3 and the dicing quality during the dicing process.

[0045] Furthermore, during the process of cutting the glass-silicon bonded wafer 100, on-line sharpening is performed. The above-mentioned on-line sharpening means that after the tool 3 cuts the glass-silicon bonded wafer 100 for a certain time or number of times (the time and number of times can be flexibly set), the tool is sharpened and then the dicing process is continued. By setting the on-line sharpening step, the tool 3 can maintain a stable cutting force during the dicing process, avoiding the problem of snake-shaped tool breakage caused by the decrease in the cutting force of the tool 3.

[0046] Specifically, the dicing machine further includes a sharpening plate, which is arranged on one side of the workbench 2 and is configured to sharpen the tool 3. By setting the sharpening plate, on-line sharpening is realized during the process of the tool 3 cutting the sharpening plate, improving the problem of the decrease in the cutting force of the tool 3.

[0047] In this embodiment, after the dicing machine is started, the workbench 2 translates along the Y-axis. The main shaft 1 is controlled so that the main shaft 1 and the tool 3 descend along the Z-axis direction to the cutting position and cut the glass-silicon bonded wafer 100 at a set rotational speed and feed rate. The above-mentioned Z-axis is the height direction, the X-axis is parallel to the axial direction of the main shaft 1, and the X-axis, Y-axis, and Z-axis are perpendicular to each other in pairs. Since the dicing process of the dicing machine is a prior art, the specific dicing steps of the dicing machine will not be elaborated herein.

[0048] Specifically, the rotational speed of the main shaft 1 in this embodiment is 23000 r / min, and the feed rate of the tool 3 is 0.5 mm / s. The selected tool 3 model is SD800, where the number 800 represents 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 tool 3 of SD800, the diamond particle size in the tool 3 is maintained within an appropriate range, ensuring sufficient cutting force of the tool 3 while reducing chipping, so that the tool 3 has a high degree of adaptability and dicing effect.

[0049] The above embodiments only illustrate the basic principles and characteristics of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, there are various changes and modifications to the present invention, and these changes and modifications all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A dicing method for a wafer, which is used to cut a glass-silicon bonded wafer (100), and the glass-silicon bonded wafer (100) includes a silicon layer (10), a glass layer (20) and a dicing protective film (30) stacked in sequence; characterized in that, The dicing method of the wafer includes: Install a tool (3) on the main shaft (1) of the dicing machine; Place the glass-silicon bonded wafer (100) on the workbench (2) of the dicing machine, and the workbench (2) adsorbs and fixes the cutting protective film (30); Start the dicing machine and cut the glass-silicon bonded wafer (100) starting from the silicon layer (10) according to the dicing parameters.

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

3. The dicing method of a wafer according to claim 2, wherein, Bake the glass-silicon bonded wafer (100) in an oven.

4. The dicing method of the wafer according to claim 3, wherein The baking temperature of the oven is 80° - 90°, and the baking time is 30 min - 60 min.

5. The dicing method of the wafer according to claim 1, wherein Sharpen the tool (3) after starting the dicing machine and before cutting the glass-silicon bonded wafer (100).

6. The dicing method of the wafer according to claim 5, wherein, Perform on-line tool sharpening during the process of cutting the glass-silicon bonded wafer (100).

7. The dicing method of the wafer according to claim 6, wherein, After starting the dicing machine, the workbench (2) translates along the Y-axis; control the main shaft (1) so that the main shaft (1) and the tool (3) descend along the Z-axis direction to the cutting position, and cut the glass-silicon bonded wafer (100) at a set rotational speed and feed rate.

8. The dicing method of a wafer according to claim 7, characterized in that, The rotational speed of the main shaft (1) is 23000 r / min, and the feed rate of the tool (3) is 0.5 mm / s.

9. Dicing machine, characterized in that, It includes a main shaft (1), a workbench (2) and a tool (3). The workbench (2) is used to adsorb and fix the glass-silicon bonded wafer (100). The tool (3) is installed on the main shaft (1), and the glass-silicon bonded wafer (100) is diced by the dicing method of the wafer according to any one of claims 1 - 8.

10. The dicing machine according to claim 9, characterized in that, The dicing machine further includes a tool sharpening plate, which is arranged on one side of the workbench (2) and is configured to sharpen the tool (3).

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