PFA wafer box correction device for 12-inch wafer

Abstract

The utility model discloses a PFA wafer box correction device for a 12-inch wafer. The correcting device comprises supporting legs, a bottom plate, supporting blocks and hexagon socket screws, and the four supporting legs are installed at the four corners of the bottom plate respectively; the four supporting blocks are respectively fixed on the upper part of the bottom plate through hexagon socket screws to form a main body structure for supporting the wafer box; the four supporting blocks are divided into front and rear supporting blocks and left and right supporting blocks, grooves are formed in the tops of the left and right supporting blocks respectively, when the PFA wafer box is erected and installed on the correcting device, the outer sides of the front and rear supporting blocks support the inner walls of the front and rear sides of the bottom of the PFA wafer box, and the inner sides of the grooves of the left and right supporting blocks support the inner walls of the left and right sides of the bottom of the PFA wafer box; when the PFA wafer box is inversely installed on the correction device, the outer sides of the front and rear supporting blocks support the front and rear inner walls of the top of the PFA wafer box, and the outer sides of the left and right supporting blocks support the left and right inner walls of the top of the PFA wafer box. According to the utility model, production accidents caused by deformation of the PFA wafer box in the production process can be reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The utility model relates to a PFA wafer cassette correction device for 12-inch wafers, belonging to the technical field of 12-inch wafer production and processing. Background Art

[0002] A PFA (Polyfluoroalkoxy) wafer cassette for wafers is an essential wafer carrier in the process of wafer production and processing, and is commonly used in the processes of wafer loading, transfer, and temporary storage. The thickness and weight of 12-inch wafers are significantly different from those of 8-inch and smaller-sized wafers. Therefore, higher requirements are also placed on the size and load-bearing capacity of the wafer cassette.

[0003] During the wafer processing, the PFA wafer cassette for 12-inch wafers is mainly used for loading wafers at the wafer loading position on the machine, carrying wafers at the wafer unloading position under the machine, transporting wafers during the wafer processing, carrying wafers for high-temperature treatment, and temporarily storing wafers in the retention tank. During this period, the PFA wafer cassette will continuously experience the pick-and-place handling of the robot, high-temperature and hot environment, acid-base corrosion environment, manual transmission process, etc. At the same time, due to the inward pulling force generated by the weight of the 12-inch wafer itself on the PFA wafer cassette, over time, it is found that the PFA wafer cassette will undergo varying degrees of deformation during the wafer processing and production. The deformation is mainly manifested as the front and rear sides and the left and right sides of the PFA wafer cassette shrinking towards the center position of the PFA wafer cassette, resulting in deformation. Among them, the deformation of the front and rear sides is more serious than that of the left and right sides, which leads to the inaccuracy of the inner diameter size of the PFA wafer cassette. From a top view, the front and rear sides of the deformed PFA wafer cassette are significantly hyperbolic.

[0004] The impacts caused by this deformation of the PFA wafer cassette in the process of wafer production and processing are mainly manifested in the following aspects: First, during the wafer loading and unloading processes on the machine, when the robot grabs and stores wafers from the PFA wafer cassette, it is extremely easy to cause abnormal pick-and-place of the robot, which will lead to robot alarms and wafer breakage. In severe cases, it will cause deformation or even breakage of the robot. Second, in the automatic wafer unloading section of the machine, when the wafer enters the PFA wafer cassette, due to the deformation of the PFA wafer cassette, the wafer cannot enter the corresponding card slots of the PFA wafer cassette according to the program settings, which will cause the wafers to be misaligned and stored, and the wafers entering the PFA wafer cassette before and after will collide, resulting in scratches, chipping, fragmentation, etc. of the wafers themselves, affecting the output and yield. When fragmentation occurs, it will also cause damage to the mechanical parts of the machine. Third, during the process of the robot and manual handling of the PFA wafer cassette, due to the fact that the PFA wafer cassette has already been deformed, plus the external force generated by the robot or human hand during the handling process, it will cause extrusion of the wafers in the wafer cassette, resulting in a risk of fragmentation. Content of the Utility Model

[0005] The purpose of the present utility model is to provide a PFA wafer cassette correction device for 12-inch wafers, which is used to correct the bent and deformed PFA wafer cassette, solve the problems of many destructive effects caused by the deformation of the PFA wafer cassette on production, equipment, etc., improve the wafer yield and recovery rate, reduce equipment loss, reduce production costs, and improve economic benefits.

[0006] To achieve the above object, the present utility model adopts the following technical solutions:

[0007] A PFA wafer cassette correction device for 12-inch wafers includes support legs, a bottom plate, support blocks, and hexagon socket head cap screws. Among them, the four support legs are respectively installed at the four corners of the bottom plate; the four support blocks are respectively fixed to the upper part of the bottom plate through hexagon socket head cap screws to form the main structure for supporting the wafer cassette; the four support blocks are divided into front and rear support blocks and left and right support blocks. Grooves are respectively provided at the tops of the left and right support blocks.

[0008] When the PFA wafer cassette is installed upright on the correction device, the outer sides of the front and rear support blocks support the front and rear inner walls of the bottom of the PFA wafer cassette, and the inner sides of the grooves of the left and right support blocks support the left and right inner walls of the bottom of the PFA wafer cassette; when the PFA wafer cassette is installed upside down on the correction device, the outer sides of the front and rear support blocks support the front and rear inner walls of the top of the PFA wafer cassette, and the outer sides of the left and right support blocks support the left and right inner walls of the top of the PFA wafer cassette.

[0009] Preferably, the distance between the front and rear support blocks and the distance between the left and right support blocks are adjustable. That is, the four support blocks are arranged to be adjustable in the front-back and left-right directions.

[0010] Preferably, a plurality of oblong holes matching the support blocks are provided on the bottom plate, and hexagon socket head cap screws are provided in the oblong holes. The left and right support blocks and the front and rear support blocks are fixed to the bottom plate through the hexagon socket head cap screws.

[0011] Preferably, the edges and corners of the support blocks are designed with rounded corners.

[0012] The advantages of the present utility model are as follows:

[0013] By using the correction device of the present utility model, due to the adjustability and special structure of the support blocks, PFA wafer cassettes with different degrees of deformation can be corrected, meeting the two installation and correction methods of upright and upside-down installation of the PFA wafer cassette. It is targeted at different PFA wafer cassettes to be corrected at the production site and can meet the correction requirements of all deformed PFA wafer cassettes at the current site, ensuring the available quantity of PFA wafer cassettes at the production site. The correction device of the present utility model can also be used repeatedly for many times.

[0014] The correction device of the present utility model can effectively restore the deformed PFA wafer cassette to its normal state, greatly reducing the probability of equipment damage and wafer breakage, playing an important role in improving the wafer processing yield, reducing costs, and increasing production efficiency, and having high practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 FIG. 1 is a schematic perspective view of a PFA wafer cassette correction device for 12-inch wafers.

[0016] Figure 2 FIG. 2 is a front view of a PFA wafer cassette correction device for 12-inch wafers.

[0017] Figure 3 FIG. 3 is a top view of a PFA wafer cassette correction device for 12-inch wafers.

[0018] Figure 4 FIG. 4 is a top view of the bottom plate of a PFA wafer cassette correction device for 12-inch wafers.

[0019] Figure 5 FIG. 5 is a schematic perspective view of the support legs of a PFA wafer cassette correction device for 12-inch wafers.

[0020] Figure 6 FIG. 6 is a schematic perspective view of a PFA wafer cassette for 12-inch wafers.

[0021] Figure 7 FIG. 7 is a comparison schematic diagram of a PFA wafer cassette for 12-inch wafers before and after correction. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The present utility model will be further described below with reference to the drawings and specific embodiments, but this does not mean limiting the protection scope of the present utility model.

[0023] As Figure 1-3 shown, the present utility model provides a PFA wafer cassette correction device for 12-inch wafers, including support legs 1, a bottom plate 2, left and right support blocks 3, front and rear support blocks 4, and hexagon socket head cap screws 5 (including spring washers and flat washers). Among them, the four support legs 1 are respectively installed at the four corners of the bottom plate; the left and right support blocks 3 and the front and rear support blocks 4 are respectively fixed to the bottom plate 2 by hexagon socket head cap screws 5 to form the main structure for supporting the wafer cassette. Grooves 31 are provided at the tops of the left and right support blocks 3, ensuring that the main part of the correction device supports the PFA wafer cassette in both upright and inverted installation modes: Combined with Figure 6Schematic diagram of the three-dimensional structure of the PFA wafer cassette for 12-inch wafers shown in the figure. When the PFA wafer cassette is installed upright on the correction device, the outer sides of the front and rear support blocks 4 support the inner walls of the front and rear sides of the bottom of the PFA wafer cassette, and the inner sides of the grooves 31 of the left and right support blocks 3 support the inner walls of the left and right sides of the bottom of the PFA wafer cassette; when the PFA wafer cassette is installed upside down on the correction device, the outer sides of the front and rear support blocks 4 support the inner walls of the front and rear sides of the top of the PFA wafer cassette, and the outer sides of the left and right support blocks 3 support the inner walls of the left and right sides of the top of the PFA wafer cassette. This design takes into account that when correcting a deformed PFA wafer cassette, the installation method of the PFA wafer cassette can be selected according to the actual situation of the deformation. The edges and corners of the support blocks 3 and 4 have been designed with rounded corners to ensure that the inner wall of the PFA wafer cassette will not be scratched when installing the PFA wafer cassette, and at the same time ensure the operation safety of the operator. As Figure 4 shown, long circular holes 21 are provided on the bottom plate 2, and hexagon socket head cap screws 5 are provided in the long circular holes 21. The left and right support blocks 3 and the front and rear support blocks 4 are fixed to the bottom plate 2 by the hexagon socket head cap screws 5. As Figure 4 shown, threaded holes 22 are provided at the four corners of the bottom plate 2. The support legs 1 are installed on the threaded holes 22 of the bottom plate 2, which not only plays a role in supporting the entire correction device, but also facilitates the movement and placement of the device.

[0024] As Figure 1 、 Figure 3 shown, when using the device of the present utility model to correct the PFA wafer cassette, the specific implementation steps are as follows: (1) Brush the PFA wafer cassette to be corrected with pure water and place it for 20-24 hours to fully dry naturally. Then install it on the correction device, and reasonably select the installation method of the PFA wafer cassette and adjust the positions of the support blocks 3 and 4 according to the deformation degree of the PFA wafer cassette and the expected correction result during the installation process; (2) Put the correction device installed with the PFA wafer cassette into a cleaning oven and perform heat treatment at 180-200 °C for 5-6 h. After the heating is completed, wait until the temperature in the cleaning oven drops below 50 °C before taking out the PFA wafer cassette and its correction device. Do not remove the correction device at this time; (3) Wait for the correction device to cool down naturally to a degree where it can be directly touched by hand, and then remove the PFA wafer cassette, and the correction is completed.

[0025] As Figure 4 shown, the bolt holes 21 on the bottom plate 2 are designed as long circular holes, which not only facilitate the installation of the support blocks 3 and 4, but also enable the support blocks 3 and 4 to have an adjustable function. By the margin left by the bolt holes 21, the distance between the front and rear and left and right of the support blocks can be changed, so that the inner cavity of the deformed PFA wafer cassette can be easily supported by the support blocks to the original size. When the support blocks are adjusted to the appropriate positions, they can be fixed to the bottom plate 2 by the hexagon socket head cap screws 5 to ensure the stability of the support, which meets the correction requirements of PFA wafer cassettes with different deformation degrees.

[0026] AsFigure 5 As shown in the figure, the support leg 1 is a cylindrical structure as a whole and has its own thread, which can be directly installed on the bottom plate 2. The height of each support leg 1 can be coordinated according to the flatness of the actual placement surface, ensuring the stability of the placement of the entire correction device. At the same time, its own height facilitates picking up, placing and moving during actual application, and also meets the space requirements for on-site equipment operation in the heat treatment process, improving the implementation efficiency of the entire correction process.

[0027] When the PFA wafer cassette correction device for 12-inch wafers of the present utility model is in use, the installation method is correctly selected according to the actual deformation part of the PFA wafer cassette. The positions of the support blocks 3 and 4 are reasonably adjusted according to the deformation situation and the required correction effect. After determining the installation method and the positions of the support blocks 3 and 4, the support blocks 3 and 4 are firmly fixed on the bottom plate 2 to ensure the support effectiveness during the entire correction process. Then, the correction is carried out according to the PFA wafer cassette correction method provided by the present utility model.

[0028] The present utility model adopts SUS304 stainless steel material, and its good characteristics meet the actual needs, being convenient and durable; at the same time, each part can be disassembled and replaced at any time, ensuring the repeatability and stability of the device.

[0029] Through actual application, the present utility model selects the way of installing the PFA wafer cassette upside down according to the on-site use scenario, and at the same time implements the correction method of the deformed PFA wafer cassette described in the present utility model. By comparing the correction data of the deformed PFA wafer cassette before and after, the inner diameter of the PFA wafer cassette is measured. The inner diameter range before correction is 175 mm to 178 mm, and the inner diameter range after correction is 180 mm to 181 mm. Figure 7 The schematic diagram of the comparison before and after the correction of the deformed PFA wafer cassette is given. It can be seen that the front and back sides of the PFA wafer cassette before correction are in a hyperbolic shape, while the front and back sides of the PFA wafer cassette after correction are parallel. The measured effect of the manipulator grasping the silicon wafer from the corrected PFA wafer cassette is significantly better than that before correction, effectively avoiding the risk of manipulator collision.

[0030] Based on the above, the PFA wafer cassette correction device for 12-inch wafers of the present utility model provides an effective solution for restoring the deformed PFA wafer cassette to a normal state during the wafer production and processing process, reducing many risks such as equipment damage, wafer breakage, low wafer yield, increased cost, and production output obstruction caused by the deformation of the PFA wafer cassette during the production process, and playing an important role in ensuring the stability of production.

Claims

1. A PFA wafer cassette correction device for 12-inch wafers, characterized in that, It includes support legs, a bottom plate, support blocks, and socket head cap screws. Among them, the four support legs are respectively installed at the four corners of the bottom plate; the four support blocks are respectively fixed to the upper part of the bottom plate by socket head cap screws to form the main structure for supporting the wafer cassette; the four support blocks are divided into two parts: front and rear support blocks and left and right support blocks. Grooves are respectively provided at the tops of the left and right support blocks. When the PFA wafer cassette is installed upright on the correction device, the outer sides of the front and rear support blocks support the front and rear inner walls of the bottom of the PFA wafer cassette, and the inner sides of the grooves of the left and right support blocks support the left and right inner walls of the bottom of the PFA wafer cassette; when the PFA wafer cassette is installed upside down on the correction device, the outer sides of the front and rear support blocks support the front and rear inner walls of the top of the PFA wafer cassette, and the outer sides of the left and right support blocks support the left and right inner walls of the top of the PFA wafer cassette.

2. The PFA wafer cassette correction device for 12-inch wafers according to claim 1, wherein The distance between the front and rear support blocks and the distance between the left and right support blocks are adjustable.

3. The PFA wafer cassette correction device for 12-inch wafers according to claim 2, characterized in that, A plurality of oblong holes matching the support blocks are provided on the bottom plate. Socket head cap screws are provided in the oblong holes, and the left and right support blocks and the front and rear support blocks are fixed to the bottom plate via the socket head cap screws.

4. The PFA wafer cassette correction device for 12-inch wafers according to any one of claims 1 to 3, characterized in that, The edges and corners of the support blocks are designed with rounded corners.

Images