Wafer polishing device

Abstract

The utility model relates to a wafer polishing device which comprises a machine frame, a material storage box, a positioning mechanism, a polishing mechanism, a feeding mechanism, a material transferring mechanism and a discharging mechanism. The positioning mechanism comprises a positioning disc, a light sensing assembly and a wavelength detector; the grinding mechanism comprises a rotary disc and a plurality of grinding discs. The rack is provided with a wafer cleaning pool. The utility model has the advantages that: (1) the front and back surfaces of the wafer are monitored and the wafer is positioned before being polished through the positioning mechanism, so that the normal polishing is ensured; and (2) according to the characteristic that the size of the wafer is small, automatic transferring, monitoring, repeated polishing and cleaning of the wafer are achieved, and the automation degree of batch processing of the wafer is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor packaging, in particular to a wafer polishing device. Background Art

[0002] The semiconductor manufacturing process involves creating complex electronic circuit technology on silicon wafers. Wafers are the basis for manufacturing integrated circuits and other electronic components. As the demand for smaller, faster, and more energy-efficient devices increases, the need for thinner wafers becomes more important. Wafer back grinding, also known as wafer thinning, is a common process in semiconductor packaging production lines.

[0003] In order to protect the circuit layer on the front side of the wafer during the wafer grinding process, grinding tape or glass is generally used to completely wrap the front side of the wafer to prevent the front side of the wafer from being damaged during the grinding process. After the grinding process is completed, the protective tape or glass on the front side of the wafer is removed.

[0004] However, in the actual operation process, the pre-grinding process involves the inspection and placement of wafers. It cannot be guaranteed that the wafers taken out from the storage box always keep the grinding surface facing up during grinding. Abnormalities such as wafers being placed in the grinder upside down often occur. Once such abnormalities occur, the grinder cannot detect them in time. Once the grinding operation begins, the wafer and the grinding wheel of the grinder will be damaged, causing economic losses.

[0005] Therefore, existing grinding devices have difficulty in real-time monitoring of the front and back sides of the wafer, which affects the efficiency of wafer batch processing. Utility Model Content

[0006] The utility model aims to provide a wafer grinding device, which can prevent wafers from being placed upside down and enhance the grinding effect and efficiency of batch wafer processing.

[0007] In order to achieve the above-mentioned utility model purpose, the utility model provides a wafer grinding device, including a frame, a material storage box, a positioning mechanism, a grinding mechanism, a loading mechanism, a material transfer mechanism, and a material unloading mechanism;

[0008] The material storage box, the positioning mechanism, the grinding mechanism, the loading mechanism, the material transfer mechanism, and the unloading mechanism are all located on the frame, and the positioning mechanism is located between the material storage box and the grinding mechanism;

[0009] The feeding mechanism is located on one side of the storage box;

[0010] The positioning mechanism includes a positioning plate, a light sensing component, and a wavelength detector, wherein the light sensing component and the wavelength detector are located above the positioning plate;

[0011] The grinding mechanism comprises a rotating disk and a plurality of grinding disks, wherein the plurality of grinding disks are distributed on the rotating disk in a circular array;

[0012] The frame is provided with a wafer cleaning pool, and the unloading mechanism is located between the polishing mechanism and the wafer cleaning pool.

[0013] Preferably, the rack is provided with an alarm component.

[0014] As a further improvement of the utility model, the grinding mechanism also includes a position sensing component, which includes a photoelectric sensing device and a plurality of sensing rods. The photoelectric sensing device is located on the frame, and the plurality of sensing rods are located on the side wall of the turntable. The installation position of each sensing rod is matched with each grinding disc, and the sensing position of the photoelectric sensing device is matched with each sensing rod.

[0015] Furthermore, the grinding disc is provided with a positioning groove.

[0016] As a further improvement of the utility model, the feeding mechanism, the material transfer mechanism, and the unloading mechanism are all provided with suction cups.

[0017] The utility model discloses a wafer polishing device, in which a loading mechanism takes out wafers from a storage box one by one and places them on a positioning plate, and firstly tests whether the placed wafers have their silicon surface facing upwards by using a wavelength detector; after ensuring that the silicon surface of the wafer is facing upwards, a light sensing component is used to locate the incision position, thereby ensuring that the transfer mechanism always contacts the center position of the wafer when transferring the wafer, so that the wafer can be placed at the center position on the polishing plate; then, each polishing plate is rotated by a turntable, and the wafer on each polishing plate is polished by each corresponding polishing piece during the intermittent rotation, and the method of multiple fine grinding is more in line with the small and thin structural characteristics of the wafer than single grinding; after resetting to the initial position, the unloading mechanism places the polished wafer into a wafer cleaning pool for cleaning.

[0018] Compared with the prior art, the wafer grinding device of the utility model has the following advantages:

[0019] (1) The positioning mechanism is used to monitor the front and back sides of the wafer and position the wafer before polishing to ensure normal polishing;

[0020] (2) Based on the small size of the wafer, the wafer can be automatically transported, monitored, polished multiple times, and cleaned, thereby improving the degree of automation in wafer batch processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of a wafer polishing device of the utility model;

[0022] Figure 2A schematic top view of the structure of a wafer polishing device of the utility model;

[0023] Figure 3 It is a schematic diagram of the positioning mechanism structure;

[0024] Figure 4 Schematic diagram of the wafer polishing process. DETAILED DESCRIPTION

[0025] The specific implementation of the utility model is further described in detail below with reference to the accompanying drawings.

[0026] like Figure 1-2 As shown, a wafer polishing device of the utility model comprises a frame 1, a material storage box 2, a positioning mechanism 3, a polishing mechanism 4, a loading mechanism 5, a material transfer mechanism 6, and a material unloading mechanism 7;

[0027] The material storage box 2, the positioning mechanism 3, the grinding mechanism 4, the feeding mechanism 5, the material transfer mechanism 6, and the unloading mechanism 7 are all located on the frame 1, and the positioning mechanism 3 is located between the material storage box 2 and the grinding mechanism 4;

[0028] The loading mechanism 5 is located at one side of the storage box 2 and is used to take out the wafers 8 one by one from the storage box 2;

[0029] like Figure 3 As shown, the positioning mechanism 3 includes a positioning plate 31, a light sensing component 32, and a wavelength detector 33, and the light sensing component 32 and the wavelength detector 33 are located above the positioning plate 31;

[0030] The two sides of the wafer are made of different materials. The front side of the wafer is made of organic materials such as glass, and the back side of the wafer is made of silicon material. The back side of the wafer needs to be polished. When the wafer 8 is placed on the positioning plate 31, the wavelength detector 33 emits light waves. Since different media reflect the emitted light waves to different degrees, the threshold of the reflection of the silicon material on the wafer 8 is set at the terminal. Only when the silicon side of the wafer 8 faces upward, the reflection value of the wafer 8 will be greater than the threshold; if the reflection value of the wafer 8 is less than the threshold, it indicates that the wafer 8 is placed incorrectly on the positioning plate 31.

[0031] In order to enable the operator to quickly discover that the polished surface of the wafer is placed upside down, an alarm component 12 may be provided on the frame 1. The alarm component 12 may be an alarm light or an alarm speaker. When the terminal receives the measured wavelength value transmitted by the wavelength detector 33, once the reflection value is less than the threshold, the terminal sends a command to the alarm component 12, and the alarm component 12 sends an alarm to the operator, so that he can deal with the upside-down wafer 8 in time.

[0032] The material transfer mechanism 6 is located between the positioning mechanism 3 and the polishing mechanism 4 , and the material transfer mechanism 6 transfers the wafer 8 on the positioning plate 31 to the polishing mechanism 4 .

[0033] After the polishing surface of wafer 8 is confirmed, the light sensing component 32 is an existing device. The light sensing component 32 senses the position of the cutout 81 of wafer 8, and by connecting with the terminal and rotating the positioning plate 31, the cutout 81 is rotated to the specified preset position, thereby realizing the positioning of wafer 8 before polishing, so that each wafer 8 placed on the positioning plate 31 is placed in a preset direction, which is convenient for positioning the center point of wafer 8. The material transfer mechanism 6 contacts the center position of wafer 8 and places it at the center position of the polishing piece 43, ensuring the polishing effect of the polishing piece 43 on wafer 8 during polishing, and avoiding deviation of the polishing position. Among them, the rotation of the positioning plate 31 is realized by an existing motor.

[0034] The grinding mechanism 4 includes a turntable 41 and a plurality of grinding discs 42, and the plurality of grinding discs 42 are distributed on the turntable 41 in a circular array; a grinding piece 43 is correspondingly arranged above each grinding disc 42, and the turntable 41 is rotated by an existing motor, and the material transfer mechanism 6 places the positioned wafer 8 on the grinding disc 42 at the idle initial position, and then the turntable 41 rotates, and the grinding disc 42 with the wafer 8 to be polished is placed to the bottom of the first grinding piece 43 for grinding, and then continues to rotate and turns to the bottom of each grinding piece 43 in turn, and resets after multiple grinding processes.

[0035] The grinding mechanism 4 also includes a position sensing component 44, which includes a photoelectric sensing device 441 and a plurality of sensing rods 442. The photoelectric sensing device 441 is located on the frame 1, and the plurality of sensing rods 442 are located on the side wall of the turntable 41. The installation position of each sensing rod 442 is adapted to each grinding disc 42, and the sensing position of the photoelectric sensing device 441 is adapted to each sensing rod 442.

[0036] The photoelectric sensing device 441 is an existing photoelectric sensor. When the sensing rod 442 rotates to the sensing position of the photoelectric sensing device 441, the photoelectric sensing device 441 converts the sensed light signal into an electrical signal and transmits it to the terminal. After the terminal obtains the signal, it sends an instruction to the motor that controls the rotation of the turntable 41, and the turntable 41 stops rotating, so that each grinding disc 42 stops under the corresponding grinding piece 43. In the process of constantly changing position, the accuracy of the grinding position of the wafer 8 is improved.

[0037] The grinding disc 42 is provided with a positioning groove 421, and the wafer 8 is located in the positioning groove 421. When the wafer 8 changes position as the turntable 41 rotates, the positioning groove 421 plays a positioning role for the wafer 8, so as to prevent the wafer 8 from being deviated on the grinding disc 42 due to the centrifugal force of the turntable 41 when the wafer 8 changes position, thereby affecting the accuracy of the grinding position.

[0038] The rack 1 is provided with a wafer cleaning pool 11, and the unloading mechanism 7 is located between the polishing mechanism 4 and the wafer cleaning pool 11. The unloading mechanism 7 places the polished wafer 8 into the wafer cleaning pool 11 to clean the residue left by the polishing of the wafer 8.

[0039] In this embodiment, the loading mechanism 5, the transfer mechanism 6, and the unloading mechanism 7 can be existing mechanical automatic arms, and the loading mechanism 5, the transfer mechanism 6, and the unloading mechanism 7 are all provided with suction cups, which are connected to the air pipes and suck the wafers by negative pressure to realize the transfer of the wafers. Compared with conventional material clamps, the use of a suction cup structure to suck the wafers is more in line with the characteristics of small and thin wafers, and can complete the transfer of wafers more smoothly.

[0040] The utility model provides a wafer polishing device, such as Figure 4 As shown, the loading mechanism 5 takes out the wafers 8 in the storage box 2 one by one and places them on the positioning plate 31. First, the wavelength detector 33 is used to test whether the placed wafer 8 is with the silicon side facing up; after ensuring that the silicon side of the wafer 8 is facing up, the photosensitive component 32 is used to pass through the positioning cutout 81 position, thereby ensuring that the transfer mechanism 6 always contacts the center position of the wafer 8 when transferring the wafer 8, so that the wafer 8 can be placed in the center position on the grinding disk 42; then, each grinding disk 42 is rotated by the turntable 41, and the wafer 8 on each grinding disk 42 is polished multiple times by each corresponding grinding piece 43 during the intermittent rotation process. Compared with single polishing, the multiple fine grinding method is more in line with the small and thin structural characteristics of the wafer; reset to the initial position; the unloading mechanism 7 puts the polished wafer 8 into the wafer cleaning pool 11 for cleaning.

[0041] The preferred embodiments of the present invention have been specifically described above, but the present invention is not limited to the described embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention, and these equivalent modifications or substitutions are all within the scope defined by the claims of this application.

Claims

1. A wafer polishing device, characterized in that: It includes a frame, a material storage box, a positioning mechanism, a grinding mechanism, a loading mechanism, a material transfer mechanism, and a material unloading mechanism; The material storage box, the positioning mechanism, the grinding mechanism, the loading mechanism, the material transfer mechanism, and the unloading mechanism are all located on the frame, and the positioning mechanism is located between the material storage box and the grinding mechanism; The feeding mechanism is located on one side of the storage box; The positioning mechanism includes a positioning plate, a light sensing component, and a wavelength detector, wherein the light sensing component and the wavelength detector are located above the positioning plate; The grinding mechanism comprises a rotating disk and a plurality of grinding disks, wherein the plurality of grinding disks are distributed on the rotating disk in a circular array; The frame is provided with a wafer cleaning pool, and the unloading mechanism is located between the polishing mechanism and the wafer cleaning pool.

2. A wafer polishing device as claimed in claim 1, characterized in that: The frame is provided with an alarm component.

3. A wafer polishing device as claimed in claim 1, characterized in that: The grinding mechanism also includes a position sensing component, which includes a photoelectric sensing device and a plurality of sensing rods. The photoelectric sensing device is located on the frame, and the plurality of sensing rods are located on the side wall of the turntable. The installation position of each sensing rod is matched with each grinding disc, and the sensing position of the photoelectric sensing device is matched with each sensing rod.

4. A wafer polishing device as claimed in claim 1 or 3, characterized in that: The grinding disc is provided with a positioning groove.

5. The wafer polishing device according to claim 1, characterized in that: The feeding mechanism, the material transfer mechanism, and the unloading mechanism are all provided with suction cups.

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