Wafer box transfer line and use method

Abstract

The invention relates to a wafer processing assembly line, in particular to a wafer box transfer line and a transfer method. The wafer box transfer line comprises a controller, a shell, a cache region located in the shell, an X-axis track and a wafer box lifting mechanism. The two ends of the cache area are provided with feeding and discharging openings correspondingly. The cache region comprises a plurality of wafer box cache tables which are transversely arranged; the wafer box lifting mechanism comprises a movable base, a Y-axis arm, a Z-axis arm and a lifting table, the Y-axis arm is fixed on the movable base, and the lifting table is arranged on the Z-axis arm in a sliding mode; an auxiliary track is arranged between the X-axis track and the buffer area, and a roller matched with the auxiliary track is arranged at the bottom of the front end of the Y-axis arm; a pressure detection head is arranged on the wafer box buffer table; the front end of the lifting table is open, and the middle of the lifting table is provided with an avoiding opening for the wafer box temporary storage table to pass through. And a detector for detecting the wafer box is arranged on the lifting table. The transferring method comprises the steps of feeding, discharging and caching. The system is high in integration level, high in operation efficiency and low in failure rate.

Description

Technical Field

[0001] The present invention relates to a wafer processing production line, and specifically to a wafer cassette transfer line and a transfer method. Background Art

[0002] Wafer processing is an important link in the semiconductor industry. At present, many domestic production lines are imported from abroad, with high costs. Most domestic production lines are small-scale equipment. Although the equipment cost is low, the working efficiency is also low. In a wafer processing production line, a wafer cassette is a tool for storing wafers. In the processing production line, it is necessary to transfer it between different stages. The current transfer methods mainly include an AVG transfer cart with a robotic arm (such as a wafer cassette handling robot disclosed in a Chinese utility model patent with the authorization announcement number CN 220882340 U) and a conveyor belt type conveyor line cooperating with a robotic arm or a lifting platform (such as a wafer cassette automatic handling production line device disclosed in a Chinese utility model with the authorization announcement number CN 219610385U). Although the AVG transfer cart is flexible and convenient, the overall integration of the production line is not high, and errors are prone to occur in the intermediate links. Moreover, the structure of the conveyor belt type conveyor line cooperating with the robotic arm or the lifting platform is not suitable for making the transfer line too long, and the one-way transfer will affect the production efficiency. In addition, the robotic arm needs to cooperate with a vision system, with high costs. The lifting platform not only has poor flexibility but also is prone to vibration during the transfer process, resulting in wafer breakage. Summary of the Invention

[0003] Aiming at the deficiencies of the above-mentioned prior art, the present invention provides a wafer cassette transfer line and a transfer method with high integration, high operation efficiency, and low failure rate.

[0004] The technical solution adopted by the present invention to solve its technical problems is as follows:

[0005] A wafer cassette transfer line includes a controller, a housing, a buffer area located inside the housing, an X-axis track, and a wafer cassette lifting mechanism arranged on the X-axis track; both ends of the buffer area are respectively provided with loading and unloading ports;

[0006] The buffer area is located in front of the X-axis track, and the buffer area includes a plurality of wafer cassette buffer platforms arranged horizontally;

[0007] The wafer cassette lifting mechanism includes a moving base, a Y-axis arm, a Z-axis arm, and a lifting platform. The Y-axis arm is fixed on the moving base, the Z-axis arm is fixed on the slide of the Y-axis arm, and the lifting platform is slidably arranged on the Z-axis arm;

[0008] A secondary track is arranged between the X-axis track and the buffer area, and rollers cooperating with the secondary track are arranged at the front bottom of the Y-axis arm;

[0009] The wafer box buffer table is fixed on the longitudinal beam, and a pressure detection head is arranged on the wafer box buffer table; the front end of the lifting platform is open and an escape opening is arranged in the middle for the wafer box buffer table to pass through; a detector for detecting the wafer box is arranged on the lifting platform, and the detector is connected to a controller.

[0010] Furthermore, the Y-axis arms are provided with two, and the lifting platform can be moved between the two Y-axis arms.

[0011] Furthermore, the detector includes detection probes arranged on the four corners of the lifting platform. When the lifting platform carrying the wafer box descends, when the four detection probes cannot detect any signal, the controller controls the lifting platform to retract along the Y-axis arm; when the lifting platform lifts the wafer box, when the four detection probes all detect signals and the lifting platform rises to a specified height, the controller controls the lifting platform to retract along the Y-axis arm.

[0012] Furthermore, the wafer box buffer station includes front and rear limiting protrusions corresponding to the bottom groove of the wafer box and left and right limiting blocks for limiting the left and right movement of the wafer box.

[0013] Furthermore, three left and right limit blocks are provided, which are respectively located at three corners of the wafer box buffer table, and a straightening slope is provided on one side of the left and right limit blocks close to the wafer box.

[0014] Furthermore, a pressure sensor is provided at the bottom of the left and right limit blocks, and the pressure sensor is connected to the controller. When the bottom edge of the wafer box touches the straightening slope, the pressure sensor sends a signal to the controller, and the controller sends an alarm signal to the host computer.

[0015] Furthermore, the straightening slopes of the left and right limit blocks are arranged on protruding parts extending outward, and the pressure sensor is located below the protruding parts; and elastic pads are arranged at the bottoms of the left and right limit blocks.

[0016] Furthermore, a buffer mechanism is arranged between the roller and the Y-axis arm, and the buffer mechanism includes a fixed seat, a sliding seat, a spring and a connecting rod. The fixed seat is fixed on the Y-axis arm, the sliding seat is slidably arranged on the fixed seat, the connecting rod is fixed on the sliding seat, and the connecting rod passes through a through hole on the fixed seat, and the spring is sleeved on the connecting rod.

[0017] A transfer method for a wafer box transfer line, comprising:

[0018] S1. Loading steps:

[0019] S11. The controller controls the wafer box lifting mechanism to move along the X-axis track to the loading port, the lifting platform extends along the Y-axis and is located at the bottom of the wafer box, and then the lifting platform lifts the wafer box at the loading port along the Z-axis. When lifting, the four detection probes of the lifting platform all detect signals and the lifting platform rises to a specified height, and then the lifting platform retreats along the Y-axis arm;

[0020] S12. The wafer box lifting mechanism moves along the X-axis track to the wafer box buffer table position specified in the buffer area, and then the lifting table extends along the Y-axis and then falls along the Z-axis. When falling, when the four detection probes of the lifting table cannot detect any signal, the lifting table retreats along the Y-axis arm to complete the material loading buffer;

[0021] S2. Cutting steps:

[0022] S21. The wafer box lifting mechanism moves along the X-axis track to the wafer box buffer table position specified in the buffer area. The lifting table is at the bottom of the Z axis. Then, the lifting table extends along the Y axis and then rises along the Z axis. When the four detection probes of the lifting table all detect signals and the lifting table rises to the specified height, the lifting table retreats along the Y axis arm;

[0023] S22. The wafer box lifting mechanism moves along the X-axis track to the unloading port, the lifting platform extends along the Y-axis, and then falls along the Z-axis. When falling, if the four detection probes of the lifting platform cannot detect any signal, the lifting platform retreats along the Y-axis arm to complete the unloading.

[0024] The beneficial effects of the present invention are:

[0025] It improves the efficiency of wafer box loading and unloading transfer by integrating a buffer area and a multi-axis wafer box lifting mechanism in the shell, and can make the transfer line six or seven meters long, greatly saving equipment installation space. The left and right limit blocks of the wafer box buffer table are provided with straightening slopes, which can straighten the falling wafer box when the wafer box lifting mechanism has displacement deviation, and the pressure sensors provided at the bottom of the left and right limit blocks can timely detect the operation deviation of the wafer box lifting mechanism on the X-axis track, and timely maintain the equipment to avoid unnecessary losses; the buffer mechanism between the roller and the Y-axis arm can prevent the wafer box lifting mechanism from being bumped during operation and causing damage to the wafer. In summary, through the above settings, the present invention achieves the beneficial effects of high integration, high operating efficiency and low failure rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 It is a schematic diagram of a part of the X-axis track and the wafer box lifting mechanism of the present invention;

[0028] Figure 3It is a schematic diagram of the wafer box lifting mechanism of the present invention;

[0029] Figure 4 It is a schematic diagram of the roller and buffer mechanism of the present invention;

[0030] Figure 5 It is a partial schematic diagram of the wafer box lifting mechanism of the present invention located at the feeding port;

[0031] Figure 6 A schematic diagram of a wafer box buffer station of the present invention;

[0032] Figure 7 It is a cross-sectional schematic diagram of the left and right limit blocks of the present invention;

[0033] In the figure, the outer shell 1, the loading port 101, the unloading port 102, the longitudinal beam 103, the buffer area 2, the X-axis track 3, the wafer box lifting mechanism 4, the movable base 401, the Y-axis arm 402, the slide 4021, the Z-axis arm 403, the lifting platform 404, the roller 405, the detection probe 406, the wafer box buffer platform 5, the pressure detection head 501, the front and rear limit protrusions 502, the left and right limit blocks 503, the straightening slope 5031, the pressure sensor 504, the elastic pad 505, the sub-track 6, the wafer box 7, the buffer mechanism 8, the fixed seat 801, the sliding seat 802, the spring 803, and the connecting rod 804. DETAILED DESCRIPTION

[0034] In order to better understand the present invention, the following Figures 1-7 , the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] First, the wafer box transfer line of the present invention is introduced:

[0036] Embodiment 1:

[0037] The wafer box transfer line of this embodiment includes a controller, a housing 1, a buffer area 2 located in the housing 1, an X-axis track 3, and a wafer box lifting mechanism 4 arranged on the X-axis track 3. The wafer box lifting mechanism 4 is driven by conventional driving components such as a transmission belt or a lead screw. A loading port 101 and a unloading port 102 are respectively arranged at both ends of the buffer area 2. The housing 1 includes a frame structure and a transparent plate mounted on the frame.

[0038] The buffer area 2 is located in front of the X-axis track 3, and the buffer area 2 includes several (such as Figure 1 Shown are 10 wafer box cache stations 5 arranged horizontally.

[0039] The wafer cassette lifting mechanism 4 includes a moving base 401, a Y-axis arm 402, a Z-axis arm 403, and a lifting platform 404. There are two symmetrically arranged Y-axis arms 402. The Y-axis arm 402 is fixed on the moving base 401. A sliding seat 4021 is arranged between the two Y-axis arms 402. The Z-axis arm 403 is fixed at the middle position of the sliding seat 4021. The lifting platform 404 is slidably arranged on the Z-axis arm 403 through a sliding seat (including a fixing plate fixed on the sliding seat 4021 and a sliding plate slidable on the fixing plate, and a driving cylinder is arranged between the fixing plate and the sliding plate). The lifting platform 404 can move between the two Y-axis arms. The initial state of the lifting platform 404 is located between the two Y-axis arms and can extend when lifting the wafer cassette.

[0040] A secondary track 6 is arranged between the X-axis track 3 and the buffer area 2. A roller 405 cooperating with the secondary track 6 is arranged at the bottom of the front end of the Y-axis arm 402.

[0041] The wafer cassette buffer table 5 is fixed on the longitudinal beam 103. A pressure detection head 501 is arranged on the wafer cassette buffer table. When the wafer cassette 7 is placed on the wafer cassette buffer table, the pressure detection head 501 detects a signal and sends the signal to the controller. The controller judges whether there is a wafer cassette on the wafer cassette buffer table 5 according to the signal of the pressure detection head 501. The pressure detection head 501 can adopt an existing product such as a pressing touch switch (also called a touch switch, a travel switch, etc.). The front end of the lifting platform 404 is open and an avoidance opening for the wafer cassette buffer table 5 to pass through is arranged in the middle. A detector for detecting the wafer cassette 7 is arranged on the lifting platform 404. The detector is connected to the controller. The detector includes detection probes 406 arranged at the four corners of the lifting platform. The detection probes 406 preferably adopt reflective photoelectric sensors. When the lifting platform 404 descends carrying the wafer cassette 7 and the four detection probes 406 all fail to detect a signal, the controller controls the lifting platform 404 to retract along the Y-axis arm 402; when the lifting platform 404 lifts the wafer cassette 7 and the four detection probes 406 all detect a signal and the lifting platform 404 rises to a specified height, the controller controls the lifting platform 404 to retract along the Y-axis arm 402.

[0042] The wafer box buffer table 5 includes front and rear limit protrusions 502 corresponding to the bottom groove of the wafer box 7 and left and right limit blocks 503 for limiting the left and right movement of the wafer box 7. Two front and rear limit protrusions 502 are symmetrically arranged. Preferably, the cross-section of the front and rear limit protrusions 502 is a trapezoid that gradually widens from top to bottom, or other structures that are narrow at the top and thick at the bottom. The purpose of setting this style is to be able to smoothly snap into the bottom groove of the wafer box. When the wafer box 7 descends to the wafer box buffer table 5, the front and rear limit protrusions 502 snap into the bottom groove of the wafer box 7, so that the wafer box 7 cannot move forward and backward, and the left and right limit blocks 503 limit the left and right movement of the wafer box 7. Furthermore, there are three left and right limit blocks 503, which are respectively located at the three corners of the wafer box buffer table 5, and the left and right limit blocks 503 are provided with a straightening slope 5031 on one side close to the wafer box.

[0043] Embodiment 2:

[0044] Since the transfer line of the present invention is relatively long, the stroke control of the wafer box lifting mechanism will inevitably deviate during operation. Therefore, this embodiment adds an operation deviation detection function based on the first embodiment, as follows:

[0045] A pressure sensor 504 is provided at the bottom of the left and right limit blocks 503, and the pressure sensor 504 is preferably a capacitive pressure sensor. The pressure sensor 504 is connected to the controller. When the bottom edge of the wafer box 7 touches the straightening slope 5031, the pressure sensor 504 sends a signal to the controller, and the controller sends an alarm signal to the host computer. The operator corrects the operation of the wafer box lifting mechanism according to the alarm signal. The straightening slope 5031 of the left and right limit blocks 503 is provided on a protruding portion extending outward, and the pressure sensor 504 is located below the protruding portion. An elastic pad 505 is provided at the bottom of the left and right limit blocks 503, such as Figure 7 As shown, the middle position of the left and right limit blocks 503 is a bolt hole, and the left and right limit blocks 503 are fixedly connected to the wafer box buffer table 5 by bolts. As long as the wafer box 7 touches the straightening slope 5031 during the downward movement, the elastic pad 505 is deformed, and the pressure sensor 504 generates a pressure value signal.

[0046] Embodiment three:

[0047] To avoid damage to the wafers caused by bumps and vibrations of the wafer cassette lifting mechanism 4 during the transfer process, a buffer mechanism is added in this embodiment on the basis of Embodiment 1 or Embodiment 2, specifically as follows: A buffer mechanism 8 is provided between the roller 405 and the Y-axis arm 402. The buffer mechanism 8 includes a fixed seat 801, a sliding seat 802, a spring 803, and a connecting rod 804. The fixed seat 801 is fixed on the Y-axis arm 402. The sliding seat 802 is slidably arranged on the fixed seat 801 through a chute-slider fit. The bottom of the connecting rod 804 is fixed on the sliding seat 802, and the upper end of the connecting rod 804 passes through a through hole on the fixed seat 801 and is provided with a blocking cap to prevent it from retracting from the through hole. The spring 803 is sleeved on the connecting rod 804. As Figure 4 shown, an auxiliary ear hole plate is also provided at the middle position of the connecting rod 804, and the connecting rod 804 passes through the auxiliary ear hole plate. When there is a bump, the sliding seat 802 moves upward against the elastic force of the spring and then resets under the action of the spring 803.

[0048] Embodiment 4:

[0049] The following introduces the transfer method of the present invention using the above wafer cassette transfer line, including,

[0050] S1. Loading step:

[0051] S11. The initial state of the lifting table is located between the two Y-axis arms. The controller controls the wafer cassette lifting mechanism to move along the X-axis track to the loading port position. There is a loading lifting table at the loading port (which is not part of the present invention and will not be described in detail. There is a wafer cassette support table with the same structure as the wafer cassette buffer table on the loading lifting table). The lifting table extends along the Y-axis to the bottom of the wafer cassette, and then the lifting table lifts the wafer cassette on the loading lifting table at the loading port along the Z-axis. When lifting, when all four detection probes of the lifting table detect signals and the lifting table rises to the specified height, the lifting table retracts along the Y-axis arm to complete the material taking step.

[0052] S12. The wafer cassette lifting mechanism moves along the X-axis track to the position of the wafer cassette buffer table specified (pre-set according to the program) in the buffer area. Then, the lifting table extends along the Y-axis and then drops along the Z-axis. When dropping, when all four detection probes of the lifting table cannot detect signals, it means that the wafer cassette has completely fallen on the wafer cassette buffer table, and the lifting table retracts along the Y-axis arm to between the two Y-axis arms to complete the loading buffer.

[0053] S2. Unloading step:

[0054] S21. The wafer cassette lifting mechanism moves along the X-axis track to the specified wafer cassette buffer table position in the buffer area. The lifting table is at the bottommost position in the Z-axis and is located between two Y-axis arms. Then, the lifting table extends along the Y-axis and then rises along the Z-axis. When all four detection probes of the lifting table detect signals and the lifting table rises to the specified height, the lifting table retracts along the Y-axis arm. At this time, the lifting table holds the wafer cassette.

[0055] S22. The wafer cassette lifting mechanism moves along the X-axis track to the unloading port. There is an unloading lifting table at the unloading port position (which is not part of the present invention and will not be described in detail. There is a wafer cassette support table with the same structure as the wafer cassette buffer table on the unloading lifting table). The lifting table extends along the Y-axis and then descends along the Z-axis. When descending, when all four detection probes of the lifting table cannot detect signals, it indicates that the wafer cassette has completely fallen onto the wafer cassette buffer table of the unloading lifting table. The lifting table retracts along the Y-axis arm to complete the unloading.

[0056] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A wafer box transfer line, characterized by: It includes a controller, a shell, a buffer area in the shell, an X-axis track, and a wafer box lifting mechanism arranged on the X-axis track; both ends of the buffer area are respectively provided with loading and unloading ports; The buffer area is located in front of the X-axis track, and the buffer area includes a plurality of wafer box buffer tables arranged laterally; The wafer box lifting mechanism comprises a movable base, a Y-axis arm, a Z-axis arm and a lifting platform, wherein the Y-axis arm is fixed on the movable base, the Z-axis arm is fixed on the slide seat of the Y-axis arm, and the lifting platform can be slidably arranged on the Z-axis arm; A secondary track is provided between the X-axis track and the buffer area, and a roller matching with the secondary track is provided at the front bottom of the Y-axis arm; The wafer box buffer table is fixed on the longitudinal beam, and a pressure detection head is arranged on the wafer box buffer table; the front end of the lifting platform is open and an escape opening is arranged in the middle for the wafer box buffer table to pass through; a detector for detecting the wafer box is arranged on the lifting platform, and the detector is connected to a controller.

2. A wafer box transfer line as claimed in claim 1, characterized in that: The Y-axis arms are provided with two, and the lifting platform can be moved between the two Y-axis arms.

3. The wafer box transfer line according to claim 1, characterized in that: The detector includes detection probes arranged on the four corners of the lifting platform. When the lifting platform carrying the wafer box descends, if the four detection probes cannot detect any signal, the controller controls the lifting platform to retreat along the Y-axis arm; when the lifting platform lifts the wafer box, if the four detection probes all detect signals and the lifting platform rises to a specified height, the controller controls the lifting platform to retreat along the Y-axis arm.

4. The wafer box transfer line according to claim 1, characterized in that: The wafer box buffering platform includes front and rear limiting protrusions corresponding to the bottom groove of the wafer box and left and right limiting blocks for limiting the left and right movement of the wafer box.

5. A wafer box transfer line as claimed in claim 4, characterized in that: There are three left and right limit blocks, which are respectively located at three corners of the wafer box buffer table. A straightening slope is arranged on one side of the left and right limit blocks close to the wafer box.

6. A wafer box transfer line as claimed in claim 5, characterized in that: A pressure sensor is arranged at the bottom of the left and right limit blocks, and the pressure sensor is connected to the controller. When the bottom edge of the wafer box touches the straightening slope, the pressure sensor sends a signal to the controller, and the controller sends an alarm signal to the host computer.

7. The wafer box transfer line according to claim 6, characterized in that: The straightening slopes of the left and right limit blocks are arranged on the protruding parts extending outwards, and the pressure sensor is located below the protruding parts; and elastic pads are arranged at the bottoms of the left and right limit blocks.

8. The wafer box transfer line according to claim 1, characterized in that: A buffer mechanism is arranged between the roller and the Y-axis arm, and the buffer mechanism includes a fixed seat, a sliding seat, a spring and a connecting rod. The fixed seat is fixed on the Y-axis arm, the sliding seat is slidably arranged on the fixed seat, the connecting rod is fixed on the sliding seat, and the connecting rod passes through a through hole on the fixed seat, and the spring is sleeved on the connecting rod.

9. A transfer method using a wafer box transfer line according to any one of claims 1 to 8, characterized in that: include S1. Loading steps: S11. The controller controls the wafer box lifting mechanism to move along the X-axis track to the loading port, the lifting platform extends along the Y-axis and is located at the bottom of the wafer box, and then the lifting platform lifts the wafer box at the loading port along the Z-axis. When lifting, the four detection probes of the lifting platform all detect signals and the lifting platform rises to a specified height, and then the lifting platform retreats along the Y-axis arm; S12. The wafer box lifting mechanism moves along the X-axis track to the wafer box buffer table position specified in the buffer area, and then the lifting table extends along the Y-axis and then falls along the Z-axis. When falling, when the four detection probes of the lifting table cannot detect any signal, the lifting table retreats along the Y-axis arm to complete the material loading buffer; S2. Cutting steps: S21. The wafer box lifting mechanism moves along the X-axis track to the wafer box buffer table position specified in the buffer area. The lifting table is at the bottom of the Z axis. Then, the lifting table extends along the Y axis and then rises along the Z axis. When the four detection probes of the lifting table all detect signals and the lifting table rises to the specified height, the lifting table retreats along the Y axis arm; S22. The wafer box lifting mechanism moves along the X-axis track to the unloading port, the lifting platform extends along the Y-axis, and then falls along the Z-axis. When falling, if the four detection probes of the lifting platform cannot detect any signal, the lifting platform retreats along the Y-axis arm to complete the unloading.

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