A wafer pushing device for unloading semiconductor wafers
Through the combination of the cylinder mechanism and the airbag spring connector, the control of the semiconductor wafer down-chip process is simplified, reducing equipment costs and reducing wafer and substrate damage.
Patent Information
- Application Number
- CN202111077301.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-09-14
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2041-09-14
AI Technical Summary
In the prior art, high-precision sensors and driving mechanisms are required during the process of lowering the semiconductor wafer, resulting in complex control and high cost, and easy damage to the wafer and substrate.
The upper suction cup device is driven by a cylinder mechanism, combined with the airbag and spring connector, and the position and pressure of the upper suction cup are controlled by gas pressure and vacuum, simplifying control requirements and reducing damage to the wafer and substrate.
This simplifies the control process, reduces equipment costs, and reduces damage to wafers and substrates during the push process.
Smart Images
Figure CN113964076B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a wafer pushing device for wafer processing, in particular to a wafer pushing device for unloading semiconductor wafers. Background Art
[0002] In the process of processing semiconductor wafers, it is usually necessary to grind and polish the back surface of the wafers. Before grinding and polishing, the wafer needs to be bonded and fixed to a substrate (such as glass, ceramic, sapphire wafer, silicon wafer, etc.) using wax or glue. After grinding and polishing, the wafer needs to be separated from the substrate, and then cleaned before entering the next process. The thickness of the ground and polished wafer is usually about 100 microns or less.
[0003] Currently, the commonly used thermal push unloading method is to heat the wafer to the pushing temperature of the wax / glue after grinding and polishing. The viscosity and adsorption capacity of the wax / glue layer become very small / weak. The wafer and the substrate are respectively sucked by vacuum suckers, and one or both of them are driven to move by a motor bracket to achieve separation.
[0004] During the wafer pushing process, generally, the lower vacuum sucker first sucks the wafer, and then the upper vacuum sucker sucks the substrate. The contact between the upper vacuum sucker and the substrate requires precise control. On the one hand, it is necessary to precisely control the downward movement of the motor or cylinder to make the upper vacuum sucker contact the substrate. On the other hand, it is necessary to detect the distance between the upper vacuum sucker and the substrate, as well as the vacuum after the upper and lower suckers suck the substrate and the wafer simultaneously and the downward pressure of the upper sucker on the wafer, to prevent the sucker from descending too fast during contact with the substrate, causing instantaneous impact and damaging the bottom wafer. Therefore, the upper vacuum sucker device requires devices such as a micrometer-level motor or cylinder position control, a cylinder pressure regulator, a micrometer-level distance sensor, and a pressure sensor to assist in safety control. The use and control of these sensors and controllers are complex and expensive. During the process of the substrate being pushed by the upper sucker, due to the position control of the cylinder or motor, a small upward lifting force is required. On the one hand, it reduces the pressure of the upper sucker on the wafer during wafer pushing, and on the other hand, it reduces the friction between the substrate and the substrate carrier after the substrate is separated from the wafer, preventing damage to the substrate. This control process also requires precise control, and the design and control are relatively complex. Summary of the Invention
[0005] Aiming at the above-mentioned defects of the prior art, the task of the present invention is to provide a wafer pushing device for unloading semiconductor wafers, which solves the problems that the movement control of the vacuum sucker relies on high-precision sensors and driving mechanisms, resulting in high control difficulty and high equipment cost, with the aim of reducing the equipment cost, reducing the control requirements, and reducing the damage to both during the wafer pushing process.
[0006] The technical solution of the present invention is as follows: A wafer pushing device for semiconductor wafers to unload wafers, including a lower heating suction cup and an upper suction cup device. The upper suction cup device is driven by a cylinder mechanism to move up and down relative to the lower heating suction cup. The upper suction cup device includes an airbag bottom plate, an airbag, an upper suction cup fixing bottom plate and an upper suction cup. The cylinder mechanism is provided with an up and down moving guide rod, and the up and down moving guide rod is fixedly connected to the airbag bottom plate. The upper suction cup is fixedly installed on the bottom surface of the upper suction cup fixing bottom plate. The upper suction cup fixing bottom plate is suspended under the airbag bottom plate through a spring connecting piece. The airbag is arranged between the airbag bottom plate and the upper suction cup fixing bottom plate and contacts the lower surface of the airbag bottom plate and the upper surface of the upper suction cup fixing bottom plate.
[0007] Further, in order to more easily adjust the elastic force of the spring connecting piece and control the downward pressure of the upper suction cup through the cooperation of the spring connecting piece and the airbag, the spring connecting piece includes a spring and a connecting column. The head of the connecting column is located above the airbag bottom plate. The tail of the screw passes through the airbag bottom plate and is fixedly connected to the upper suction cup fixing bottom plate. The spring is sleeved on the connecting column between the head of the connecting column and the upper surface of the airbag bottom plate. Through the connection of this spring connecting piece, a spring with a sufficient length can be set to cooperate with the airbag pressure to form a downward pressure, and an upward restoring force can be formed when the airbag is evacuated to better complete the separation of the substrate and the wafer.
[0008] Further, the connecting column is a screw.
[0009] Further, in order to ensure the balance of pressure, the spring connecting pieces are equally distributed around the airbag bottom plate in a number of not less than three.
[0010] Further, in order to prevent the air path connecting the airbag from interfering with the movement of the upper suction cup device, the up and down moving guide rod is a hollow tube, and the up and down moving guide rod passes through the airbag bottom plate and is communicated with the airbag.
[0011] Further, the wafer pushing device includes a machine table and a moving bracket. The moving bracket is horizontally movably arranged on the machine table. The lower heating suction cup is fixedly arranged on the machine table. The cylinder mechanism is arranged on the moving bracket. The up and down moving guide rod is arranged on the moving bracket and is guided up and down by the moving bracket.
[0012] Further, the moving bracket includes a cross beam. The cylinder mechanism includes a cylinder and a support seat. The cylinder rod of the cylinder is fixedly connected to the support seat. The up and down moving guide rod is connected to the support seat.
[0013] Further, in order to balance the acting force of the cylinder on the up and down moving guide rod, there are two cylinders, and the cylinders are located on both sides of the up and down moving guide rod.
[0014] Furthermore, the moving bracket includes a column and an up-and-down moving bracket. Both ends of the up-and-down moving bracket are guided up and down by the column, and the airbag bottom plate is fixedly connected to the up-and-down moving bracket.
[0015] The advantages of the present invention compared with the prior art are as follows:
[0016] The device of the present invention does not require precise down-force sensors and position / height sensors. The cylinder mechanism is used for preliminary height positioning, and then the pressure and the descending height of the upper suction cup are controlled by the spring connecting piece, the gas pressure and the vacuum inside the airbag, so as to meet the requirements for the position and pressure control of the upper suction cup during the wafer pushing process, and the damage to the substrate and the wafer during the wafer pushing process can be reduced. The device has a simple structure, low cost and is easy to control. Description of the Drawings
[0017] Figure 1 It is a schematic structural diagram of a wafer pushing device for unloading semiconductor wafers.
[0018] Figure 2 It is a schematic structural diagram of the upper suction cup device.
[0019] Figure 3 It is a schematic cross-sectional structural diagram of the upper suction cup device.
[0020] Figure 4 It is a schematic diagram when the upper suction cup device is at the highest position.
[0021] Figure 5 It is a schematic diagram when the upper suction cup device is descending.
[0022] Figure 6 It is a schematic diagram of the adsorption and fitting of the upper suction cup and the substrate.
[0023] Figure 7 It is a schematic diagram during the separation of the wafer and the substrate.
[0024] Figure 8 It is a schematic diagram after the separation of the wafer and the substrate. Detailed Embodiments
[0025] The present invention will be further described below in conjunction with embodiments, but it is not intended to limit the present invention.
[0026] Please refer to Figure 1As shown in the figure, the pusher device for unloading semiconductor wafers involved in this embodiment includes a base 100. A moving bracket 1 is arranged on the base 100, and the moving bracket 1 can move horizontally to generate the moving power and support during wafer pushing. The lower heating suction cup 2 is arranged on the base 100 and is used for heating and adsorbing the wafer. The wafer carrier 3 is arranged on the base 100 on the side of the lower heating suction cup 2 and is used for placing the substrate wafer after wafer pushing. The moving bracket 1 is provided with two columns and a cross beam. The cross beam is fixed at the top of the columns. The columns are provided with vertical guide grooves. The up and down moving bracket 4 is mainly used for fixing the upper suction cup device 5. Both ends of the up and down moving bracket 4 are arranged in the guide grooves of the columns, and the columns are used for guiding the up and down movement. On the cross beam of the moving bracket 1, two cylinders 6 are vertically arranged. The cylinders 6 are used to control the movement of the upper suction cup device 5. The cylinder rods of the cylinders 6 are arranged upward, and the top of the cylinder rods is connected to both ends of a support seat 9. A downward limit 7 can be arranged on the cylinder 6 to limit and control the lowest position of the support seat 9, and the height of the downward limit 7 can be adjusted to meet the needs of different heights. A hollow up and down moving guide rod 8 is fixed in the middle of the support seat 9. The up and down moving guide rod 8 is located between the two cylinders 6, passes through the cross beam and the up and down moving bracket 4 and is connected to the upper suction cup device 5. The top of the up and down moving guide rod 8 is connected to a swivel joint 10. Through the swivel joint 10 and the up and down moving guide rod 8, vacuum or inflation is provided to increase the pressure for the upper suction cup device 5.
[0027] Please refer to Figure 2 and Figure 3 As shown in the figure, the upper suction cup device 5 is mainly used for controlling the up and down position of the upper suction cup 15 and adsorbing the substrate. The upper suction cup device 5 includes an airbag bottom plate 11, an airbag 19, an upper suction cup fixing bottom plate 13 and an upper suction cup 15. The airbag bottom plate 11 is fixed on the up and down moving bracket 4, and the airbag 19 is fixed on the airbag bottom plate 11 through an airbag fixing ring 18. The airbag 19 is located between the airbag bottom plate 11 and the upper suction cup fixing bottom plate, contacts the lower surface of the airbag bottom plate 11 and the upper surface of the upper suction cup fixing bottom plate 13, and the up and down moving guide rod 8 passes through the airbag bottom plate 11 and is in communication with the airbag 19. The upper suction cup fixing bottom plate 13 is suspended below the airbag bottom plate 11 by three spring screws 12. Specifically, a spring screw 12 is respectively arranged at the circumferentially equally divided positions on the circular airbag bottom plate 11. The head of the spring screw 12 is located above the airbag bottom plate 11. The tail of the spring screw 12 passes through the airbag bottom plate 11 and is fixed to the upper suction cup fixing bottom plate 13, and the spring is connected between the head of the spring screw 12 and the upper surface of the airbag bottom plate 11. When the airbag 19 is filled with compressed air, the airbag 19 bulges, and can overcome the elastic force of the spring to press down the upper suction cup fixing bottom plate 13, making it move downward. The upper suction cup vacuum back plate 14 is connected below the upper suction cup fixing bottom plate 13, and the upper suction cup 15 is fixed to the upper suction cup vacuum back plate 14, and vacuum is provided to the upper suction cup 15 through the vacuum inlet 16.
[0028] Please refer to Figures 4 to 8As shown in the figure, the process of pushing the wafer using the wafer pushing device of the present invention is as follows: Before the wafer pushing starts, the upper suction cup is at the highest position. At this time, the pipeline 17 in the vertical movement guide rod 8 is connected to vacuum, and the airbag 19 contracts and clings tightly. Under the action of the spring screw 12, the upper suction cup fixed base plate 13 contracts and clings tightly to the airbag fixing ring 18. The cylinder 6 pushes upward to the highest position. At this time, the distance between the surface of the upper suction cup 15 and the surface of the substrate 22 on the lower heating suction cup 2 below is H1. (H1 > 30 mm). After starting to push the wafer, after the cylinder 6 operates, the cylinder rod contracts, the support seat 9 moves downward, and the vertical movement guide rod 8 causes the upper suction cup device 5 together with the vertical movement bracket 4 to fall as a whole. Limited by the downward limit 7, the upper suction cup 15 is initially in place. At this time, the distance between the surface of the upper suction cup 15 and the surface of the substrate 22 on the lower heating suction cup 2 below is H2 (0.5 mm <= H2 <= 5 mm). Then, compressed air with controllable pressure is introduced into the pipeline 17, and the airbag 19 begins to bulge. Under the dual action of the upward push of the airbag 9 (the airbag bulges) and the spring screw 12 (the spring is compressed), the upper suction cup fixed base plate 13 starts to move downward by a distance T1. At the same time, the upper suction cup 15 is connected to vacuum. When the distance between the surface of the upper suction cup 15 and the surface of the substrate 22 on the lower heating suction cup 2 is approximately 0, the upper suction cup 15 adsorbs the substrate 22, and the vacuum monitoring value of the upper suction cup 15 changes. When the vacuum stabilizes to a certain value, it indicates that the upper suction cup 15 has completely adsorbed the substrate 22, and the movement of the moving bracket 1 can be controlled to separate the wafer from the substrate. Finally, the moving bracket 1 is controlled to move horizontally, thereby driving the upper suction cup device 5 to move horizontally together. At this time, the lower heating suction cup 2 continues to evacuate to adsorb the wafer 21. The pipeline 17 is switched to vacuum. Under the elastic restoring force of the spring screw 12, the upper suction cup fixed base plate 13 has an upward spring pushing force, and at the same time, there is a downward adhesion force of the wafer 21 below due to wax / glue adhering to the substrate 22. When the upward acting force of the spring screw 12 is greater than the downward adhesion force of the wafer 21 on the substrate 22, the wafer 21 is separated from the substrate 22, and the distance between the bottom of the substrate 22 and the surface of the wafer 21 is H3.
[0029] The surface of the wafer carrier 3 is flush with the surface of the lower heating suction cup 2. The moving bracket 1 drives the upper suction cup device 5 to continue moving horizontally to the center of the wafer carrier 3. The bottom of the substrate 22 always maintains a certain distance from the surface of the wafer carrier 3 to prevent friction with the surface of the substrate 22. When moving to the center of the wafer carrier 3, the vacuum of the upper suction cup 15 is switched to compressed air, and the compressed air blows the substrate 22 onto the surface of the wafer carrier 3. Then the cylinder 6 operates to lift the entire upper suction cup device 5 to the top, and then the moving bracket 1 returns to the initial position, completing the entire hot wafer pushing process.
Claims
1. A wafer pushing device for unloading semiconductor wafers, characterized in that, It includes a lower heating suction cup, an upper suction cup device, a machine table and a moving bracket. The upper suction cup device is driven by a cylinder mechanism to move up and down relative to the lower heating suction cup. The upper suction cup device includes an airbag bottom plate, an airbag, an upper suction cup fixed bottom plate and an upper suction cup. The cylinder mechanism is provided with an up-and-down moving guide rod which is fixedly connected to the airbag bottom plate. The upper suction cup is fixedly installed on the bottom surface of the upper suction cup fixed bottom plate. The upper suction cup fixed bottom plate is suspended under the airbag bottom plate through a spring connecting piece. The airbag is arranged between the airbag bottom plate and the upper suction cup fixed bottom plate and contacts the lower surface of the airbag bottom plate and the upper surface of the upper suction cup fixed bottom plate. The spring connecting piece includes a spring and a connecting column. The head of the connecting column is located above the airbag bottom plate. The tail of the connecting column passes through the airbag bottom plate and is fixedly connected to the upper suction cup fixed bottom plate. The spring is sleeved on the connecting column between the head of the connecting column and the upper surface of the airbag bottom plate. The moving bracket is horizontally movably arranged on the machine table. The moving bracket includes an up-and-down moving bracket. The airbag bottom plate is fixedly connected to the up-and-down moving bracket. The lower heating suction cup is fixedly arranged on the machine table. The cylinder mechanism is arranged on the moving bracket. The up-and-down moving guide rod is arranged on the moving bracket and is guided up and down by the moving bracket. During the process of pushing the wafer, after the upper suction cup adsorbs the substrate, the moving bracket moves and drives the upper suction cup device to move. The airbag is set to be vacuum. Under the elastic restoring force of the spring, the substrate is separated from the wafer.
2. The wafer pushing device for semiconductor wafer unloading according to claim 1, characterized in that, The connecting column is a screw.
3. The wafer pushing device for unloading semiconductor wafers according to claim 1, characterized in that, The spring connecting pieces are equally distributed around the airbag bottom plate in a number of not less than three.
4. The wafer pushing device for unloading semiconductor wafers according to claim 1, characterized in that, The up-and-down moving guide rod is a hollow tube. The up-and-down moving guide rod passes through the airbag bottom plate and is communicated with the airbag.
5. The wafer pushing device for unloading semiconductor wafers according to claim 1, characterized in that, The moving bracket includes a cross beam. The cylinder mechanism includes a cylinder and a support seat. The cylinder rod of the cylinder is fixedly connected to the support seat. The up-and-down moving guide rod is connected to the support seat.
6. The wafer pushing device for unloading semiconductor wafers according to claim 5, characterized in that, There are two cylinders. The cylinders are located on both sides of the up-and-down moving guide rod.
7. The wafer pushing device for unloading semiconductor wafers according to claim 1, characterized in that, The moving bracket further includes a column. Both ends of the up-and-down moving bracket are guided up and down by the column.
Citation Information
Patent Citations
Wafer and glass separating device and method
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Automatic debonding machine
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