Double-disc wafer thinning machine

Abstract

The utility model relates to a kind of double-sand-wheel wafer thinning machine, including rack, main shaft system, polishing head feed mechanism and control system.The main shaft system includes the main shaft driven by motor, and main shaft is supported by air bearing assembly;The coaxial installation of main shaft front end is composed of double-sand-wheel structure by inner sand wheel and outer sand wheel, and inner sand wheel is coarse grinding sand wheel, and outer sand wheel is fine grinding sand wheel, and they are connected by a gear transmission mechanism and can be driven to rotate.The core of the utility model is that, by integrating the coarse grinding sand wheel and fine grinding sand wheel arranged inside and outside on the same main shaft, and cooperating with the polishing head feed mechanism that can be lifted, the coarse grinding and fine grinding processing of wafer is automatically completed under one equipment and one clamping.Effectively solve the problems, such as low efficiency, high cost and complicated operation, caused by the need for two devices or replacing sand wheel in the prior art, significantly improve the efficiency and automation degree of wafer thinning processing.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor manufacturing equipment technology, and in particular to a dual-grinding-wheel wafer thinning machine, specifically a grinding device for wafer back-side thinning processing, and especially a dual-grinding-wheel wafer thinning machine that integrates rough grinding and fine grinding functions. Background Technology

[0002] Wafer thinning is a critical step in semiconductor packaging, aiming to remove material from the back of the wafer to achieve the desired thickness through grinding. Existing single-axis wafer thinning machines are typically equipped with only one grinding wheel, and a single machine can only complete one of the two processes: rough grinding or fine grinding. To complete the entire thinning process, two solutions are usually adopted: one is to complete rough grinding on one machine, then stop the machine to replace the fine grinding wheel and perform fine grinding again. This method is cumbersome, time-consuming, labor-intensive, and has low production efficiency. The other is to use two independent machines connected in series to form a production line, one dedicated to rough grinding and the other to fine grinding. Although this method improves efficiency, the equipment purchase cost is high, the footprint is large, and the risk of clamping errors and surface contamination caused by the transfer of wafers between different machines is increased.

[0003] Therefore, the industry urgently needs a wafer thinning equipment that can integrate rough grinding and fine grinding functions, and is efficient and cost-effective. Utility Model Content

[0004] To address the shortcomings of existing technologies, the purpose of this utility model is to provide a dual-grinding wafer thinning machine, which is a compact, highly automated, and efficient dual-grinding wafer thinning machine that can complete both rough and fine grinding of wafers in a single setup on a single machine.

[0005] The above-mentioned utility model objective is achieved through the following technical solution:

[0006] A dual-grinding-wheel wafer thinning machine includes a frame, a spindle system mounted on the frame, a drive device for driving the spindle system to rotate, a feed mechanism for controlling the up-and-down movement of the grinding head, and a control system. The spindle system includes a spindle and a grinding wheel mounting structure fixed to the front end of the spindle. An inner grinding wheel and an outer grinding wheel are coaxially mounted on the grinding wheel mounting structure. The inner grinding wheel is a coarse grinding wheel, and the outer grinding wheel is a fine grinding wheel. The inner grinding wheel and the outer grinding wheel are connected by a gear transmission mechanism.

[0007] As a further technical solution of this utility model: the gear transmission mechanism is an external gear structure.

[0008] As a further technical solution of this utility model: the spindle system also includes a water jacket sleeved outside the spindle, the water jacket being provided with coolant inlet and outlet for providing cooling and rinsing to the grinding area.

[0009] As a further technical solution of this utility model: the spindle is supported on the frame by an air bearing assembly.

[0010] As a further technical solution of this utility model: the feeding mechanism is a programmable Z-axis servo feeding mechanism, which is used to drive the entire spindle system and grinding wheel mounting structure to rise and fall along the Z-axis, so as to realize the switching between the rough grinding station and the fine grinding station.

[0011] As a further technical solution of this utility model: the driving device is a main spindle motor, which directly drives the main spindle through a coupling.

[0012] As a further technical solution of this utility model: the control system is electrically connected to the drive device and the feed mechanism, and is used to control the start and stop of the spindle and its speed, as well as the lifting and lowering actions and position of the feed mechanism.

[0013] In summary, this utility model has at least one of the following beneficial technical effects:

[0014] 1. This utility model discloses a dual-grinding-wheel wafer thinning machine, including a frame, a spindle system, a grinding head feed mechanism, and a control system. The spindle system includes a motor-driven spindle supported by an air bearing assembly; a dual-grinding-wheel structure consisting of an inner grinding wheel and an outer grinding wheel is coaxially mounted at the front end of the spindle. The inner grinding wheel is a coarse grinding wheel, and the outer grinding wheel is a fine grinding wheel. The two are connected by a gear transmission mechanism and can be driven to rotate. The core of this utility model lies in the fact that by integrating coarse and fine grinding wheels arranged internally and externally on the same spindle, and cooperating with a height-adjustable grinding head feed mechanism, the coarse and fine grinding of wafers can be automatically completed in one machine and one clamping. This effectively solves the problems of low efficiency, high cost, and cumbersome operation caused by the need for two machines or changing grinding wheels in the prior art, and significantly improves the efficiency and automation of wafer thinning processing.

[0015] 2. High efficiency integration: Through the innovative coaxial dual grinding wheel design, the rough grinding and fine grinding functions are integrated into one machine, eliminating the time for grinding wheel replacement or workpiece transfer, and greatly improving production efficiency.

[0016] 3. Ensure accuracy: All grinding processes are completed in one clamping, avoiding positioning errors caused by multiple clamping, and improving machining accuracy and product consistency.

[0017] 4. Reduced costs: Saves on the purchase cost of a piece of equipment, reduces factory floor space and labor costs.

[0018] 5. High degree of automation: The entire rough grinding-fine grinding process can be completed automatically by the control system, reducing human intervention, operation difficulty and human error. Attached Figure Description

[0019] Figure 1 This is the front view of the present invention.

[0020] Figure 2 for Figure 1 Sectional view along the middle AA.

[0021] Reference numerals in the attached drawings: 1. Frame; 2. Spindle; 3. Air bearing assembly; 4. Spindle motor; 5. Inner grinding wheel; 6. Outer grinding wheel; 7. Water jacket; 8. Gear transmission mechanism; 9. Feed mechanism. Detailed Implementation

[0022] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0023] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0025] Example 1:

[0026] Reference Figure 1 and Figure 2This utility model discloses a dual-grinding-wheel wafer thinning machine, including a frame 1, a spindle 2 system mounted on the frame 1, a drive device for driving the spindle 2 system to rotate, a feed mechanism 9 for controlling the up and down movement of the grinding head, and a control system. The spindle 2 system includes a spindle 2 and a grinding wheel mounting structure fixed to the front end of the spindle 2. An inner grinding wheel 5 and an outer grinding wheel 6 are coaxially mounted on the grinding wheel mounting structure. The inner grinding wheel 5 is a coarse grinding wheel, and the outer grinding wheel 6 is a fine grinding wheel. The inner grinding wheel 5 and the outer grinding wheel 6 are connected by a gear transmission mechanism 8.

[0027] Its innovation lies in the fact that the grinding wheel mounting structure has two grinding wheels coaxially mounted, one inner coarse grinding wheel and one outer fine grinding wheel. The coarse grinding wheel and the fine grinding wheel are connected by a gear transmission mechanism 8 to achieve power transmission. The feed mechanism 9 is used to drive the spindle 2 system to move up and down along the Z-axis, thereby switching the dual grinding wheel structure between the coarse grinding station and the fine grinding station.

[0028] The gear transmission mechanism 8 is an external gear structure. The drive device is the spindle motor 4, which directly drives the spindle 2 via a coupling. The control system is electrically connected to the drive device and the feed mechanism 9, and is used to control the start, stop, and speed of the spindle 2, as well as the lifting and lowering movements and position of the feed mechanism 9. In this embodiment, the control system is a programmable logic controller (PLC), used to coordinate and control the speed of the spindle motor 4, the motion sequence, and the position of the feed mechanism 9.

[0029] The spindle 2 system also includes a water jacket 7 fitted outside the spindle 2. The water jacket 7 has coolant inlets and outlets for providing cooling and flushing to the grinding area. The water jacket 7 supplies coolant to the grinding area, serving to cool, lubricate, and flush away debris. The spindle 2 is supported on the frame 1 by an air bearing assembly 3. The spindle 2 is supported by high-precision air bearings to ensure stability and machining accuracy during high-speed rotation. The feed mechanism 9 is a programmable Z-axis servo feed mechanism used to drive the entire spindle 2 system and the grinding wheel mounting structure to move up and down along the Z-axis, enabling switching between rough grinding and fine grinding positions. In this embodiment, the feed mechanism 9 is a precision ball screw mechanism driven by a servo motor.

[0030] The frame 1 serves as the supporting foundation for the entire equipment. The spindle 2 is mounted on the frame 1 via a high-precision air bearing assembly 3, ensuring extremely high rigidity and stability during high-speed rotation. The spindle motor 4 is connected to the rear end of the spindle 2 via a coupling, providing it with rotational power.

[0031] The front end of spindle 2 is designed with a grinding wheel mounting structure. The coarse grinding wheel (inner grinding wheel 5) is directly mounted on the end of spindle 2 via a flange. The fine grinding wheel (outer grinding wheel 6) is sleeved on the outside of the coarse grinding wheel via a bearing. The coarse and fine grinding wheels are connected by an external gear transmission mechanism 8. When spindle 2 rotates, the power drives the fine grinding wheel to rotate in the same or opposite direction (depending on the gear design) synchronously via the gear transmission mechanism 8. A water jacket 7, sleeved on the outside of spindle 2, is connected to an external cooling system to precisely deliver coolant to the grinding areas of the two grinding wheels.

[0032] The entire spindle 2 system is mounted on a precision feed mechanism 9 driven by a servo motor. This feed mechanism 9 can drive the entire spindle 2 system to move up and down precisely along the Z-axis (vertical direction).

[0033] The working principle of this utility model is as follows:

[0034] During operation, the wafer to be processed is fixed to the worktable below by a vacuum chuck (not shown in the figure). The control system executes the following steps according to a preset program:

[0035] Rough grinding stage: The feed mechanism 9 drives the spindle 2 system to descend, causing the rough grinding wheel to contact the wafer surface. The spindle motor 4 starts, driving the dual grinding wheels to rotate for rough grinding. After reaching the set thickness, the feed mechanism 9 drives the spindle 2 system to rise, causing the rough grinding wheel to detach from the wafer.

[0036] Fine grinding stage: The feed mechanism 9 continues to descend precisely by a preset displacement, causing the external fine grinding wheel to contact the rough-ground wafer surface. The spindle 2 continues to rotate for fine grinding and polishing. After fine grinding is completed, the feed mechanism 9 drives the spindle 2 system to fully return to its original position.

[0037] Coolant was continuously supplied throughout the entire machining process. At this point, the rough and finish grinding processes were completed in a single setup.

[0038] The implementation principle of this utility model is as follows: This utility model discloses a dual-grinding wheel wafer thinning machine, including a frame 1, a spindle 2 system, a grinding head feed mechanism 9, and a control system. The spindle 2 system includes a motor-driven spindle 2, which is supported by an air bearing assembly 3. A dual-grinding wheel structure consisting of an inner grinding wheel 5 and an outer grinding wheel 6 is coaxially mounted at the front end of the spindle 2. The inner grinding wheel 5 is a coarse grinding wheel, and the outer grinding wheel 6 is a fine grinding wheel. The two are connected by a gear transmission mechanism 8 and can be driven to rotate. The core of this utility model is that by integrating coarse and fine grinding wheels arranged internally and externally on the same spindle 2, and cooperating with a height-adjustable grinding head feed mechanism 9, the coarse and fine grinding of wafers can be automatically completed in one machine and one clamping. This effectively solves the problems of low efficiency, high cost, and cumbersome operation caused by the need for two machines or changing grinding wheels in the prior art, and significantly improves the efficiency and automation of wafer thinning processing.

[0039] The embodiments described herein are preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape, and principle of this utility model should be included within the scope of protection of this utility model.

Claims

1. A dual-grinding-wheel wafer thinning machine, comprising a frame (1), a spindle (2) system mounted on the frame (1), a drive device for driving the spindle (2) system to rotate, a feed mechanism (9) for controlling the up-and-down movement of the grinding head, and a control system, characterized in that: The spindle (2) system includes a spindle (2) and a grinding wheel mounting structure fixed to the front end of the spindle (2). An inner grinding wheel (5) and an outer grinding wheel (6) are coaxially mounted on the grinding wheel mounting structure. The inner grinding wheel (5) is a coarse grinding wheel, and the outer grinding wheel (6) is a fine grinding wheel. The inner grinding wheel (5) and the outer grinding wheel (6) are connected by a gear transmission mechanism (8).

2. The dual-grinding-wheel wafer thinning machine according to claim 1, characterized in that: The gear transmission mechanism (8) is an external gear structure.

3. A dual-grinding-wheel wafer thinning machine according to claim 1 or 2, characterized in that: The spindle (2) system also includes a water jacket (7) sleeved outside the spindle (2), and the water jacket (7) is provided with coolant inlet and outlet for providing cooling and flushing to the grinding area.

4. A dual-grinding-wheel wafer thinning machine according to claim 3, characterized in that: The spindle (2) is supported on the frame (1) by an air bearing assembly (3).

5. A dual-grinding-wheel wafer thinning machine according to claim 1, characterized in that: The feed mechanism (9) is a programmable Z-axis servo feed mechanism used to drive the entire spindle (2) system and grinding wheel mounting structure to rise and fall along the Z-axis, so as to realize the switching between the rough grinding station and the fine grinding station.

6. The dual-grinding-wheel wafer thinning machine according to claim 1, characterized in that: The drive device is a spindle motor (4), which directly drives the spindle (2) through a coupling.

7. A dual-grinding-wheel wafer thinning machine according to claim 1, characterized in that: The control system is electrically connected to the drive device and the feed mechanism (9) and is used to control the start and stop of the spindle (2) and its speed, as well as the lifting and lowering action and position of the feed mechanism (9).

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