A wafer positioning and calibration device based on roller clamping drive

Abstract

The present invention relates to a wafer positioning and calibration device based on roller clamping drive, comprising a fixed plate, a pair of clamping units arranged in parallel on the side of the fixed plate, a wafer notch calibration mechanism arranged on the side of the fixed plate and located between the two clamping units, and a translation limit mechanism arranged on the side of the fixed plate and adapted to the clamping unit, wherein the clamping unit comprises a cylinder driving mechanism arranged on the side of the fixed plate, a motor mounting seat connected to the cylinder driving mechanism in transmission, and a pair of roller driving mechanisms arranged in parallel on the motor mounting seat. Compared with the prior art, the present invention locates the center of the wafer by clamping the outer edge of the wafer with a roller, does not contact the center of the wafer, and does not have the risk of contaminating the wafer; the wafer is driven to rotate together by a roller, and the contact point between the roller and the outer edge of the wafer is not a fixed point, thereby avoiding the defects of the clamping block blocking the wafer notch and the optical fiber being unable to detect the wafer notch in the prior art.

Description

Technical Field

[0001] The invention belongs to the technical field of wafer processing and relates to a wafer positioning and calibration device based on roller clamping drive. Background Art

[0002] The processing of semiconductor devices includes many steps, and each step uses different processing equipment. To ensure that the processing of semiconductor devices can proceed smoothly, the wafer needs a fixed position and posture when entering many steps, so that the subsequent steps can accurately process the wafer, which requires the wafer to be positioned and calibrated in advance. In order to facilitate the positioning and calibration of the wafer, a notch (or straight edge) is generally left on the wafer. The wafer calibrator that can locate the center of the wafer and find the position of the notch (or straight edge) on the wafer has become one of the indispensable equipment in the processing of semiconductor devices.

[0003] There are two main methods used in the wafer calibrator currently used in the market. One is a laser sensor combined with a translation and rotation table structure with a vacuum suction cup. The vacuum suction cup fixes the wafer, and the translation and rotation table translates and locates the center of the wafer. The laser sensor determines the edge position of the wafer and finds the notch (or straight edge) of the wafer for calibration through the rotation of the translation and rotation table. The second is a laser sensor combined with a clamping and rotation table structure. The clamping block of the clamping and rotation table locates the center of the wafer by clamping the edge of the wafer, and the laser sensor finds the notch of the wafer for calibration through the rotation of the clamping and rotation table. Both methods have certain defects. The vacuum suction cup of the former will inevitably contact the center of the wafer, which poses the risk of contaminating the wafer. The latter is not only complex in structure, but also when the clamping block of the clamping and rotation table is clamped at the notch of the wafer, even if the clamping and rotation table rotates repeatedly, the laser sensor cannot find the notch of the wafer, resulting in calibration failure. Summary of the invention

[0004] The purpose of the present invention is to provide a wafer positioning and calibration device based on roller clamping drive, which clamps the outer edge of the wafer by rollers and drives the wafer to rotate, and cooperates with optical fiber sensors to achieve positioning and calibration of the wafer.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A wafer positioning and calibration device based on roller clamping drive, the device comprises a fixed plate, a pair of clamping units arranged in parallel on the side of the fixed plate, a wafer gap calibration mechanism arranged on the side of the fixed plate and located between the two clamping units, and a translation limit mechanism arranged on the side of the fixed plate and adapted to the clamping unit, wherein the clamping unit comprises a cylinder driving mechanism arranged on the side of the fixed plate, a motor mounting seat connected to the cylinder driving mechanism, and a pair of roller driving mechanisms arranged in parallel on the motor mounting seat. The wafer to be positioned and calibrated is placed between the four roller driving mechanisms of the two clamping units, the cylinder driving mechanism drives the two motor mounting seats to move towards each other, so that the four roller driving mechanisms clamp the wafer in the middle, and at the same time the translation limit mechanism limits the displacement of the motor mounting seat to determine the center position of the wafer; then the four roller driving mechanisms rotate simultaneously to drive the wafer to rotate, and the wafer gap calibration mechanism detects the edge of the wafer, and when the wafer gap is found, the roller driving mechanism stops rotating, and the positioning and calibration of the wafer is completed at this time.

[0007] Furthermore, the cylinder drive mechanism includes a linear slide rail horizontally arranged on the side of the fixed plate and a clamping cylinder arranged on the side of the fixed plate and transmission-connected to the motor mounting seat, and one end of the motor mounting seat is fixedly connected to the slider of the linear slide rail.

[0008] Preferably, each cylinder drive mechanism comprises two linear guide rails arranged in parallel.

[0009] Furthermore, a cylinder shaft connecting plate is provided between the clamping cylinder and the motor mounting seat, and the cylinder shaft of the clamping cylinder is connected to the motor mounting seat via the cylinder shaft connecting plate.

[0010] Furthermore, the roller driving mechanism includes a stepper motor vertically arranged on a motor mounting seat and a roller arranged on the top of the stepper motor and connected to the stepper motor in a transmission manner. The stepper motor can drive the roller to rotate.

[0011] Furthermore, the roller comprises a roller truncated cone portion fixedly connected to the motor shaft of the stepper motor and a roller cylindrical portion arranged on the top of the roller truncated cone portion, and a roller notch is provided between the top of the roller truncated cone portion and the bottom of the roller cylindrical portion. The outer edge of the wafer is located in the roller notch.

[0012] Furthermore, the outer diameter of the roller truncated cone gradually increases from top to bottom, the outer diameter of the bottom surface of the roller truncated cone is larger than the outer diameter of the roller cylindrical portion, and the outer diameter of the top surface of the roller truncated cone is smaller than the outer diameter of the roller cylindrical portion. The inclined surface on the roller truncated cone can guide the wafer.

[0013] Furthermore, the wafer notch calibration mechanism includes an optical fiber holder arranged on the side of the fixing plate and an optical fiber sensor arranged on the optical fiber holder. The opposite-beam optical fiber sensor is adapted to the wafer notch.

[0014] Furthermore, the optical fiber holder includes an upper optical fiber holder and a lower optical fiber holder, and the optical fiber sensor is a beam-type optical fiber sensor, including an optical fiber transmitting end and an optical fiber receiving end, and the optical fiber transmitting end and the optical fiber receiving end are respectively arranged on the upper optical fiber holder and the lower optical fiber holder. The detection light emitted by the optical fiber transmitting end can reach the optical fiber receiving end through the wafer notch, thereby calibrating the wafer notch.

[0015] Furthermore, the translation limiting mechanism includes a limiting block arranged on the side of the fixed plate and adapted to one of the motor mounting seats. The limiting block is fixedly arranged on the side of the fixed plate. When the four roller drive mechanisms clamp the wafer, the translation position of one of the motor mounting seats is limited by the limiting block to locate the center of the wafer.

[0016] Furthermore, the translation limiting mechanism further includes a buffer assembly arranged on the side of the fixed plate and adapted to another motor mounting seat, the buffer assembly including a buffer mounting seat arranged on the side of the fixed plate and a buffer arranged on the buffer mounting seat. The buffer facilitates controlling the clamping force of the roller on the wafer.

[0017] Compared with the prior art, the present invention has the following characteristics:

[0018] 1) The center of the wafer is located by clamping the outer edge of the wafer with rollers, without touching the center of the wafer, and there is no risk of contaminating the wafer;

[0019] 2) A fixed position limit block is used to locate the center of the wafer after the roller clamps it. The center of the wafer is accurately located, and a buffer is further used to control the clamping force of the roller on the wafer. It is safe and reliable, and the roller will not damage the wafer.

[0020] 3) A stepper motor is used to drive the roller to rotate. After the roller clamps the wafer, the friction between the roller and the wafer drives the wafer to rotate together. The contact point between the roller and the outer edge of the wafer is not a fixed point, which avoids the defects of the clamping block blocking the wafer notch and the optical fiber being unable to detect the wafer notch in the prior art;

[0021] 4) Four sets of stepper motors and rollers are used to drive the wafer to rotate, so that at least three rollers are in contact with the outer edge of the wafer, avoiding the problem of the wafer center deviation caused by the wafer retreating when one of the rollers hits the wafer notch;

[0022] 5) The present invention has a simple structure, is easy to implement and has low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 It is a schematic diagram of the matching structure between the roller drive mechanism and the outer edge of the wafer in the present invention;

[0025] Description of the markings in the figure:

[0026] 1—fixed plate, 2—linear slide rail, 3—motor mounting seat, 4—stepping motor, 5—roller, 501—roller truncated cone portion, 502—roller cylindrical portion, 503—roller notch, 6—clamping cylinder, 7—cylinder shaft connecting plate, 8—buffer mounting seat, 9—buffer, 10—limiting block, 11—optical fiber holder, 12—optical fiber sensor, 13—wafer, 131—wafer notch. DETAILED DESCRIPTION

[0027] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0028] Embodiment 1:

[0029] A wafer positioning and calibration device based on roller clamping drive, the structure of which is as follows Figure 1 As shown, it includes a fixing plate 1, a linear slide rail 2, a motor mounting seat 3, a stepper motor 4, a roller 5, a clamping cylinder 6, a cylinder shaft connecting plate 7, a buffer mounting seat 8, a buffer 9, a limit block 10, a fiber optic seat 11 and a fiber optic sensor 12. There are four linear slide rails 2, four stepper motors 4 and rollers 5, two motor mounting seats 3, two clamping cylinders 6, two cylinder shaft connecting plates 7 and two fiber optic seats 11. The fiber optic sensor 12 is a counter-radiation type fiber optic sensor. The wafer notch 131 is a notch on the wafer 13. The four stepper motors 4 are driven by the same driver.

[0030] like Figure 1 As shown, the fixed plate 1 is the main mounting plate, the linear slide 2 is mounted on the side of the fixed plate 1, the motor mounting seat 3 is symmetrically mounted on the slider of the linear slide 2, the stepper motor 4 is mounted on the motor mounting seat 3, the motor shaft is facing upward, the roller 5 is mounted on the motor shaft of the stepper motor 3 and locked by a set screw, the clamping cylinder 6 is symmetrically mounted on the side of the fixed plate 1, located on the inner side of the linear slide 2, and connected to the motor mounting seat 3 through the cylinder shaft connecting plate 7, the buffer mounting seat 8 and the limit block 10 are symmetrically mounted on the side of the fixed plate 1, located above the clamping cylinder 6, the buffer 9 is mounted on the buffer mounting seat 8, and the head of the buffer 9 faces the left motor mounting seat 3, the center of the wafer 13 coincides with the center of the combination of the four rollers 5, and is located in the roller notch 503 in the height direction (see Figure 2), the optical fiber holder 11 is installed at the side center of the fixing plate 1, located at the upper and lower sides of the wafer 13, and the optical fiber sensor 12 is installed in the groove of the optical fiber holder 11.

[0031] Combine the following Figure 1 , Figure 2 The use process of the wafer positioning and calibration device is further explained.

[0032] 1) Initial state: the cylinder shaft of the clamping cylinder 6 is extended, the motor mounting seat 3 drives the stepper motor 4 and the roller 5 to open to both sides, and the stepper motor 4 does not operate;

[0033] 2) Loading: Place the wafer 13 between the four rollers 5, between the roller notches 503 in height direction;

[0034] 3) Positioning the center of the wafer 13: The cylinder shaft of the clamping cylinder 6 is retracted, and the motor mounting seat 3 drives the stepping motor 4 together with the roller 5 to translate inward, and the wafer 13 is clamped by the roller 5 under the inclined surface guidance of the roller truncated table portion 501 (see Figure 2 ), the limit block 10 blocks the right motor mounting seat 3 from continuing to translate inward, the rollers 5 on the two stepper motors 4 on the right control the position of the wafer 13, the head of the buffer 9 bears against the motor mounting seat 3 on the left, and the buffer 9 relies on elastic force to ensure that the rollers 5 on the two stepper motors 4 on the left are in contact with the wafer 13 and maintain the set clamping force, and the center positioning of the wafer 13 is completed;

[0035] 4) Finding the wafer notch 131: After the center of the wafer 13 is positioned, the four stepper motors 4 start to run synchronously, and the motor shafts and rollers 5 rotate together. The rollers 5 drive the wafer 13 to rotate by the friction between the rollers 5 and the outer edge of the wafer 13, and the optical fiber sensor 12 detects the edge of the wafer 13. When the wafer notch 131 does not reach the optical fiber sensor 12, the detection light emitted by the transmitting end of the optical fiber sensor 12 is blocked by the wafer 13 and cannot reach the receiving end of the optical fiber sensor 12, and the optical fiber sensor 12 has no detection signal; when the wafer notch 131 reaches the optical fiber sensor 12, the detection light emitted by the transmitting end of the optical fiber sensor 12 passes through the wafer notch 131 and reaches the receiving end of the optical fiber sensor 12, and the optical fiber sensor 12 sends a signal that the wafer notch 131 is found, and the four stepper motors 4 stop running at the same time immediately, and the wafer 13 maintains the current posture waiting to be taken out, and the wafer notch 131 is found;

[0036] 5) Unloading: The cylinder shaft of the clamping cylinder 6 extends out, and the motor mounting seat 3 drives the stepping motor 4 and the roller 5 to open to both sides, and the wafer 13 falls onto the inclined surface of the roller truncated table 501, and the wafer 13 that has been positioned and calibrated is taken out and the wafer 13 is sent to the next process while maintaining the existing posture and position;

[0037] 6) Repeat steps 1) to 5) until all wafers 13 are positioned and calibrated.

[0038] Embodiment 2:

[0039] like Figure 1 The wafer positioning and calibration device based on roller clamping drive shown in the figure includes a fixed plate 1, a pair of clamping units arranged in parallel on the side of the fixed plate 1, a wafer gap calibration mechanism arranged on the side of the fixed plate 1 and located between the two clamping units, and a translation limit mechanism arranged on the side of the fixed plate 1 and adapted to the clamping unit. The clamping unit includes a cylinder driving mechanism arranged on the side of the fixed plate 1, a motor mounting seat 3 transmission-connected to the cylinder driving mechanism, and a pair of roller driving mechanisms arranged in parallel on the motor mounting seat 3.

[0040] The cylinder driving mechanism includes a linear slide rail 2 horizontally arranged on the side of the fixed plate 1 and a clamping cylinder 6 arranged on the side of the fixed plate 1 and connected to the motor mounting seat 3. One end of the motor mounting seat 3 is fixedly connected to the slider of the linear slide rail 2. A cylinder shaft connecting plate 7 is provided between the clamping cylinder 6 and the motor mounting seat 3, and the cylinder shaft of the clamping cylinder 6 is connected to the motor mounting seat 3 through the cylinder shaft connecting plate 7.

[0041] The roller drive mechanism includes a stepper motor 4 vertically arranged on a motor mounting seat 3 and a roller 5 arranged on the top of the stepper motor 4 and connected to the stepper motor 4. Figure 2 As shown, the roller 5 includes a roller truncated cone portion 501 fixedly connected to the motor shaft of the stepper motor 4 and a roller cylindrical portion 502 arranged on the top of the roller truncated cone portion 501, and a roller notch 503 is provided between the top of the roller truncated cone portion 501 and the bottom of the roller cylindrical portion 502. The outer diameter of the roller truncated cone portion 501 gradually increases from top to bottom, the outer diameter of the bottom surface of the roller truncated cone portion 501 is larger than the outer diameter of the roller cylindrical portion 502, and the outer diameter of the top surface of the roller truncated cone portion 501 is smaller than the outer diameter of the roller cylindrical portion 502.

[0042] The wafer notch calibration mechanism includes a fiber holder 11 disposed on the side of the fixing plate 1 and a fiber sensor 12 disposed on the fiber holder 11. The fiber holder 11 includes an upper fiber holder and a lower fiber holder, and the fiber sensor 12 is a beam-type fiber sensor, including a fiber emitting end and a fiber receiving end, and the fiber emitting end and the fiber receiving end are disposed on the upper fiber holder and the lower fiber holder, respectively.

[0043] The translation limiting mechanism includes a limiting block 10 arranged on the side of the fixed plate 1 and adapted to one of the motor mounting seats 3. The translation limiting mechanism also includes a buffer assembly arranged on the side of the fixed plate 1 and adapted to the other motor mounting seat 3, and the buffer assembly includes a buffer mounting seat 8 arranged on the side of the fixed plate 1 and a buffer 9 arranged on the buffer mounting seat 8.

[0044] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A wafer positioning and calibration device based on roller clamping drive, characterized in that: The device comprises a fixed plate (1), a pair of clamping units arranged in parallel on the side of the fixed plate (1), a wafer notch calibration mechanism arranged on the side of the fixed plate (1) and located between the two clamping units, and a translation limit mechanism arranged on the side of the fixed plate (1) and adapted to the clamping units, wherein the clamping unit comprises a cylinder drive mechanism arranged on the side of the fixed plate (1), a motor mounting seat (3) drivingly connected to the cylinder drive mechanism, and a pair of roller drive mechanisms arranged in parallel on the motor mounting seat (3); The roller drive mechanism is provided with four groups, including a stepper motor (4) vertically arranged on a motor mounting seat (3) and a roller (5) arranged on the top of the stepper motor (4) and connected to the stepper motor (4); The roller (5) comprises a roller truncated cone portion (501) fixedly connected to the motor shaft of the stepping motor (4) and a roller cylindrical portion (502) arranged on the top of the roller truncated cone portion (501), and a roller notch (503) is provided between the top of the roller truncated cone portion (501) and the bottom of the roller cylindrical portion (502); The outer diameter of the roller truncated cone portion (501) gradually increases from top to bottom, the outer diameter of the bottom surface of the roller truncated cone portion (501) is larger than the outer diameter of the roller cylindrical portion (502), and the outer diameter of the top surface of the roller truncated cone portion (501) is smaller than the outer diameter of the roller cylindrical portion (502); The cylinder drive mechanism comprises a linear slide rail (2) horizontally arranged on the side of the fixed plate (1) and a clamping cylinder (6) arranged on the side of the fixed plate (1) and connected to the motor mounting seat (3) in a transmission manner, and one end of the motor mounting seat (3) is fixedly connected to the slider of the linear slide rail (2); A cylinder shaft connecting plate (7) is provided between the clamping cylinder (6) and the motor mounting seat (3), and the cylinder shaft of the clamping cylinder (6) is connected to the motor mounting seat (3) via the cylinder shaft connecting plate (7); The wafer notch calibration mechanism comprises an optical fiber holder (11) arranged on the side of the fixing plate (1) and an optical fiber sensor (12) arranged on the optical fiber holder (11); The optical fiber seat (11) comprises an upper optical fiber seat and a lower optical fiber seat, and the optical fiber sensor (12) is a beam-type optical fiber sensor, comprising an optical fiber transmitting end and an optical fiber receiving end, wherein the optical fiber transmitting end and the optical fiber receiving end are respectively arranged on the upper optical fiber seat and the lower optical fiber seat; The use process of the wafer positioning calibration device includes: 1) Initial state: The cylinder shaft of the clamping cylinder is extended, the motor mounting seat drives the stepper motor and the roller to open to both sides, and the stepper motor does not run; 2) Loading: Place the wafer between the four rollers, between the roller notches in height direction; 3) Positioning the center of the wafer: The cylinder shaft of the clamping cylinder retracts, and the motor mount drives the stepper motor and the roller to translate inward. The wafer is clamped by the roller under the inclined guide of the roller truncated table. The limit block prevents the right motor mount from continuing to translate inward. The rollers on the two stepper motors on the right control the position of the wafer. The head of the buffer supports the motor mount on the left. The buffer relies on elastic force to ensure that the rollers on the two stepper motors on the left are in contact with the wafer and maintain the set clamping force. The center positioning of the wafer is completed; 4) Finding the wafer notch: After the wafer center is positioned, the four stepper motors start to run synchronously, and the motor shafts and rollers rotate together. The rollers drive the wafer to rotate by the friction between the rollers and the outer edge of the wafer. The optical fiber sensor detects the edge of the wafer. When the wafer notch does not reach the optical fiber sensor, the detection light emitted by the transmitting end of the optical fiber sensor is blocked by the wafer and cannot reach the receiving end of the optical fiber sensor, and the optical fiber sensor has no detection signal; when the wafer notch reaches the optical fiber sensor, the detection light emitted by the transmitting end of the optical fiber sensor passes through the wafer notch and reaches the receiving end of the optical fiber sensor. The optical fiber sensor sends a signal that the wafer notch is found, and the four stepper motors stop running at the same time. The wafer maintains its current posture and waits to be taken out, and the wafer notch search is completed; 5) Unloading: The cylinder shaft of the clamping cylinder extends out, and the motor mounting seat drives the stepper motor and the roller to open to both sides, and the wafer falls onto the inclined surface of the roller truncated table. The wafer that has been positioned and calibrated is taken out and the current posture and position are maintained to send the wafer to the next process; 6) Repeat steps 1) to 5) until all wafers are positioned and calibrated.

2. The wafer positioning and calibration device based on roller clamping drive according to claim 1 is characterized in that: The translation limiting mechanism comprises a limiting block (10) which is arranged on the side of the fixing plate (1) and is matched with one of the motor mounting seats (3).

3. The wafer positioning and calibration device based on roller clamping drive according to claim 2 is characterized in that: The translation limiting mechanism also includes a buffer assembly arranged on the side of the fixed plate (1) and adapted to another motor mounting seat (3), the buffer assembly including a buffer mounting seat (8) arranged on the side of the fixed plate (1) and a buffer (9) arranged on the buffer mounting seat (8).

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