A high-precision wafer loading device for thinning process

Abstract

This invention belongs to the field of wafer manufacturing and fabrication, and particularly relates to a high-precision wafer loading device for a thinning process. The device includes a chuck, a sliding shaft connected to the chuck, and a bearing sleeved on the sliding shaft. The bearing is connected to the chuck via a bearing fixing component. Several spring plates are disposed between the bearing fixing component and the chuck. One end of each spring plate is fixed to a spherical bearing fixing component, and the other end is fixed to the top of the chuck. When the bearing and the chuck move relative to each other, the spring plates push the bearing back to its original position. This invention can reduce the clearance error between the moving shaft and the bearing, thereby improving the wafer loading accuracy.

Description

Technical Field

[0001] This invention belongs to the field of wafer manufacturing and preparation, and particularly relates to a high-precision wafer loading device for thinning processes. Background Technology

[0002] With the development of domestic semiconductor technology, the demand for ultra-thin wafer fabrication processes has become increasingly strong. However, as wafer thickness decreases, the wafer fragmentation rate increases exponentially, resulting in low wafer yield. To improve wafer yield, edge-retention thinning processes are currently commonly used to fabricate wafers. (See [link to relevant documentation]). Figure 1 As shown, the edge thinning process involves grinding or polishing the inner part of the wafer to form a thinning layer, while retaining the outer edge of the wafer, which does not participate in the thinning process. This provides outer protection and strength support for the thinned layer. The thickness of the wafer center thinning layer prepared by the edge thinning process is ≤60um.

[0003] However, due to the high tolerance requirements for the edge ring in wafer processing, the overall precision requirements after positioning, the wafer loading process, and the thinning process via the rotating feeding table are even higher. The existing wafer loading process uses a harmonic reducer to rotate the transmission arm and then press down the wafer loading hand suction cup component. (See [link to relevant documentation]). Figure 2 As shown, the wafer loading suction cup component includes a suction cup, a sliding shaft connected to the upper part of the suction cup, and a sliding bearing sleeved on the outside of the sliding shaft. When the suction cup presses down to place the wafer and / or picks up the wafer on the positioning stage, it will generate an impact, causing the sliding bearing to slide and produce a small-amplitude eccentric displacement of uncertain position. The sliding clearance between the sliding shaft and the sliding bearing is 0.01-0.02mm. After the wafer picking and placing actions, the cumulative error can reach a maximum of 0.04mm. The error range of 0.04mm accounts for a large proportion of the error requirements that need to be controlled for wafers, resulting in extremely high precision requirements for wafer positioning and the subsequent wafer picking process, making the process more difficult and leading to a decrease in wafer yield. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a high-precision wafer loading device for thinning processes, which can reduce the clearance error between the movable shaft and the bearing, thereby improving the wafer loading accuracy.

[0005] A high-precision film loading device for a thinning process includes a suction cup, a sliding shaft connected to the suction cup, a bearing sleeved on the sliding shaft, and the bearing connected to the suction cup via a bearing fixing component.

[0006] Several spring plates are provided between the bearing fixing component and the suction cup. One end of the spring plate is fixed to the bearing fixing component, and the other end is fixed to the top of the suction cup. When the bearing and the suction cup move relative to each other, the spring plate pushes the bearing back to its original position.

[0007] According to an embodiment of the present invention, the bearing is a sliding bearing or a spherical bearing, for example, a spherical bearing.

[0008] According to an embodiment of the present invention, the device further includes a spring plate pressure plate, which is used to fix one end of the spring plate to the bearing fixing member. Preferably, the spring plate pressure plate presses the spring plate onto the bearing fixing member. For example, the spring plate pressure plate, the spring plate and the bearing fixing member are connected by bolts.

[0009] According to an embodiment of the present invention, the device further includes a leveling mechanism connected to the suction cup for adjusting the suction cup to a horizontal position.

[0010] According to an embodiment of the present invention, the horizontal adjustment mechanism includes a plurality of adjustment shafts, one end of which is fixed to the top of the suction cup, and the other end passes through the bearing fixing member and is exposed outside the bearing fixing member.

[0011] According to an embodiment of the present invention, the horizontal adjustment mechanism further includes an adjustment cap for cooperating with the adjustment shaft. The adjustment cap is movably connected to the adjustment shaft, and when the adjustment cap rotates, it can adjust the height of the suction cup.

[0012] According to an embodiment of the present invention, a plurality of the adjustment shafts are evenly distributed along the center of the suction cup.

[0013] According to an embodiment of the present invention, the horizontal adjustment mechanism includes at least two adjustment shafts, preferably three to six adjustment shafts, for example, three adjustment shafts.

[0014] According to an embodiment of the present invention, the structure of the spring plate is set according to actual needs, preferably L-shaped or Z-shaped, for example, L-shaped.

[0015] According to an embodiment of the present invention, the number of spring plates is set according to actual needs, preferably greater than or equal to 2, and more preferably, the number of spring plates is greater than or equal to 4, for example, 4.

[0016] According to an embodiment of the present invention, the spring plates are uniformly distributed along the bearing.

[0017] According to an embodiment of the present invention, the structure of the spring plate can be set according to actual needs, and can be an integral structure or an independent structure.

[0018] According to an embodiment of the present invention, when the structures are independent of each other, each spring plate is pressed onto the corresponding spring plate.

[0019] According to an embodiment of the present invention, when the spring plate is an integral structure, the spring plate has a hole at the location corresponding to the bearing to provide a clearance for the bearing to move.

[0020] According to an embodiment of the present invention, one end of the spring plate connected to the bearing fixing member is disposed at any position outside the bearing fixing member, preferably disposed at the top outer edge of the bearing fixing member, for example, in the area between the adjusting cap and the edge of the bearing fixing member.

[0021] According to an embodiment of the present invention, the diameter of the suction cup is 2 to 12 inches, and the suction surface of the suction cup is smaller than the diameter of the suction cup, which is 2 to 4 inches.

[0022] Beneficial effects

[0023] 1) This invention adds a spring plate between the bearing fixing component and the suction cup to limit the lateral movement of the bearing. Based on the elasticity of the spring plate, under non-yielding conditions, the bearing and suction cup return to their initial positions after each pick-up and drop. The spring plate pressure plate ensures the shape of the spring plate. The adjusting nut and adjusting shaft work together to adjust the level of the suction cup. After adjustment, the spring plate maintains the position of the suction cup each time. The suction cup has a small adsorption surface (2-4 inches in diameter), ensuring the stability of the suction piece. The connection with the upper spring plate increases the ability to effectively adjust the level of the suction cup.

[0024] 2) The bearing in this invention is a spherical bearing. By changing the sliding shaft and the sliding bearing to a sliding shaft and the spherical bearing moving in opposite directions, the mechanism can be prevented from seizing.

[0025] 3) This invention ensures that the bearing and chuck return to their initial positions each time a wafer is picked up or placed, further reducing randomly generated eccentric displacement and maintaining the accuracy of each wafer pick-up or placement within 2-5µm. Even after both wafer pick-up and placement actions on the wafer positioning stage and wafer placement stage using the chuck, no cumulative error occurs, keeping the error of this component consistently within 2-5µm. This meets the requirements of the wafer edge thinning process and reduces the accuracy requirements of subsequent processes. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the existing edge-reduction process;

[0027] Figure 2 This is a schematic diagram of the upper hand suction cup component in the prior art;

[0028] Figure 3 This is a schematic diagram of the high-precision wafer loading device for the thinning process in this invention;

[0029] Figure 4 for Figure 3 A sectional view.

[0030] Among them, 1-spring plate, 2-spring plate, 3-adjusting shaft, 4-adjusting cap, 5-spherical bearing, 6-bearing fixing part, 7-suction cup, 8-sliding shaft. Detailed Implementation

[0031] The structure of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0032] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, 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 this invention.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] Example 1

[0035] A high-precision film loading device for a thinning process includes a suction cup 7, a sliding shaft 8, spring plates 2, and a horizontal adjustment mechanism. The sliding shaft 8 is connected to the top of the suction cup 7, and a bearing 5 is sleeved on the sliding shaft 8. The bearing 5 is connected to the suction cup 7 through a bearing fixing member 6. Several spring plates 2 are arranged between the bearing fixing member 6 and the suction cup 7. One end of the spring plate 2 is fixed to the bearing fixing member 6, and the other end is fixed to the top of the suction cup 7. When the bearing 5 and the suction cup 7 move relative to each other, the spring plate 2 pushes the bearing 5 back to its original position. In this embodiment, the bearing 5 is a sliding bearing or a spherical bearing, for example, a spherical bearing.

[0036] The spring plate 2 is connected to the bearing fixing member 6 via the spring plate pressure plate 1. The spring plate pressure plate 1 is used to press one end of the spring plate 2 onto the bearing fixing member 6. For example, the spring plate pressure plate 1, the spring plate 2 and the bearing fixing member 6 are connected by bolts.

[0037] The structure of the spring plate 2 is set according to actual needs, preferably L-shaped or Z-shaped, for example, L-shaped; the number of spring plates 2 is set according to actual needs, preferably greater than or equal to 2, and more preferably, the number of spring plates 2 is greater than or equal to 4, for example, 4.

[0038] In this embodiment, the spring plates 2 are evenly distributed along the bearing 5.

[0039] The structure of the spring plate 1 can be set according to actual needs. It can be an integral structure or an independent structure. When the spring plate 1 is an independent structure, each spring plate 1 is pressed onto the corresponding spring plate 2. When the spring plate 1 is an integral structure, holes are opened at the corresponding positions of the spring plate 1 and the bearing 5 to provide a clearance for the bearing 5 to move.

[0040] A horizontal adjustment mechanism is connected to the suction cup 7 and is used to adjust the suction cup 7 to a horizontal position. In this embodiment, the horizontal adjustment mechanism includes several adjustment shafts 3 and a matching adjustment cap 4. One end of the adjustment shaft 3 is fixed to the top of the suction cup 7, and the other end passes through the bearing fixing member 6 and is exposed outside the bearing fixing member 6. The adjustment cap 4 is movably connected to the part of the adjustment shaft 3 that extends out of the bearing fixing member 6. When the adjustment cap 4 rotates, the height of the suction cup 7 can be adjusted.

[0041] In this embodiment, the end of the spring plate 2 connected to the bearing fixing member 6 is located at any position outside the bearing fixing member 6, preferably at the top outer edge of the bearing fixing member 6, for example, in the area between the adjusting cap and the edge of the bearing fixing member 6.

[0042] In this embodiment, the horizontal adjustment mechanism includes at least two adjustment shafts 3, preferably three to six adjustment shafts 3, for example, three adjustment shafts 3, and the adjustment shafts 3 are evenly distributed along the center of the suction cup 7.

[0043] The specific embodiments of the present invention have been described above by way of example. However, the scope of protection of the present invention is not limited to the above exemplary embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A high-precision wafer loading device for a thinning process, comprising a suction cup, characterized in that, A sliding shaft is connected to the suction cup, and a bearing is sleeved on the sliding shaft. The bearing is connected to the suction cup through a bearing fixing component. Several spring plates are provided between the bearing fixing component and the suction cup. One end of the spring plate is fixed to the outer edge of the spherical bearing fixing component, and the other end is fixed to the top of the suction cup. The spring plates are evenly distributed along the bearing and are L-shaped or Z-shaped. When the bearing and the suction cup move relative to each other, the spring plates push the bearing back to its original position. The bearing is a spherical bearing; The upper plate device also includes a spring plate pressure plate, which is used to fix one end of the spring plate to the bearing fixing member.

2. The high-precision wafer loading device for the thinning process according to claim 1, characterized in that, The loading device also includes a horizontal adjustment mechanism connected to the suction cup for adjusting the suction cup to a horizontal position. The horizontal adjustment mechanism includes several adjustment shafts, one end of which is fixed to the top of the suction cup, and the other end passes through the bearing fixing member and is exposed outside the bearing fixing member.

3. The high-precision wafer loading device for the thinning process according to claim 2, characterized in that, The leveling mechanism also includes an adjusting cap for cooperating with the adjusting shaft. The adjusting cap is movably connected to the adjusting shaft, and when the adjusting cap rotates, it can adjust the height of the suction cup.

4. The high-precision wafer loading device for the thinning process according to claim 2, characterized in that, Several of the adjustment shafts are evenly distributed along the center of the suction cup.

5. The high-precision wafer loading device for thinning process according to any one of claims 1-4, characterized in that, The spring plate and pressure plate can be an integral structure or independent structures.

6. The high-precision wafer loading device for the thinning process according to claim 5, characterized in that, When the spring plate pressure plates are independent structures, each spring plate pressure plate is pressed onto the corresponding spring plate.

7. The high-precision wafer loading device for the thinning process according to claim 5, characterized in that, When the spring plate is an integral structure, the spring plate has holes at the corresponding positions with the bearing to provide clearance for the bearing to move.

8. The high-precision wafer loading device for the thinning process according to claim 1, characterized in that, The suction cup has a diameter of 2 to 12 inches, and the suction surface of the suction cup is smaller than the diameter of the suction cup, which is 2 to 4 inches.

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