Automatic wafer alignment device and method

Abstract

The present invention provides a wafer automatic alignment device and method, including: an image acquisition component composed of a camera with a crosshair mark on the lens surface, a motion component that performs fixed value movement through a grating ruler, a data processing component, a wafer tray for carrying wafers to be aligned, and a probe card for aligning the wafers to be aligned; the image acquisition component is used to collect images of the wafer tray, the probe card and the wafer to be aligned, and transmit the images to the data processing component; the data processing component is used to process the received image data and calculate the alignment parameters according to the data; the wafer tray is connected and fixed to the motion component, and the wafer tray is driven to move by the motion component. The present invention performs wafer alignment through image recognition and grating ruler positioning, and can simultaneously complete alignment in three directions: X, Y and Z; without the aid of a calibration block, the difficulty of installation and the steps of alignment operation are reduced; the alignment method is simple, the data processing is more accurate, and the alignment accuracy and efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the field of wafer processing, and in particular to an automatic wafer alignment device and method. Background Art

[0002] Wafer probe station is a device that supports the tester to test the performance and quality of each chip on the wafer in the front process of semiconductor chip manufacturing. It is an essential link to ensure the quality of chip manufacturing and reduce manufacturing costs and losses. After the wafer manufacturing is completed, it is necessary to enter the wafer testing stage. Wafer testing uses the tester to test each die on the chip through the combination of the probe station and the probe. The probe is used to make direct contact with the pad on the die so that the tester can directly input or output signals to the chip. Its test parameters include the DC parameters and AC parameters of the chip.

[0003] Existing wafer probe stations mostly use test alignment, which uses the collected wafer image to make preliminary adjustments to the probe card, perform test alignment, make further adjustments based on the needle marks of the test alignment, perform test alignment again, and repeat the above steps multiple times until the needle marks are located at the center of the pad on the wafer, completing the alignment. The above alignment method has the disadvantages of complex operation and poor stability.

[0004] Invention patent No. CN105486995B "Fully automatic probe station image positioning device and visual alignment method" proposes a needle alignment device and method for precise needle alignment with the help of a calibration block. This method can achieve high-precision needle alignment, but involves too many formulas and too many calculations. During the calculation process, errors are easily generated due to the manufacturing accuracy or installation accuracy of the calibration block, affecting the needle alignment accuracy and reducing the needle alignment efficiency. Summary of the invention

[0005] In order to solve the shortcomings of the above-mentioned wafer alignment method, the present invention provides a high-precision and high-efficiency wafer automatic alignment device and method without the aid of a calibration block.

[0006] To achieve the above object, the present invention adopts the following specific technical solutions:

[0007] A wafer automatic alignment device comprises: an image acquisition component composed of a camera with a crosshair mark on the lens surface, a motion component that performs fixed-distance motion through a grating ruler, a data processing component, a wafer tray for carrying wafers to be aligned, and a probe card for aligning the wafers to be aligned; the image acquisition component is used to acquire images of the wafer tray, the probe card and the wafer to be aligned, and transmit the images to the data processing component; the data processing component is used to process the received image data and calculate the alignment parameters according to the data; the wafer tray is connected and fixed to the motion component, and the wafer tray is driven to move by the motion component.

[0008] Preferably, the image acquisition component includes: a downward-looking camera and an upward-looking camera; the downward-looking camera is fixed and unchanged in position, and serves as a reference camera, with its lens facing downward, to acquire images of the wafer tray, the upward-looking camera, and the wafer to be aligned; the upward-looking camera is connected and fixed to the motion component, and moves horizontally with the wafer tray, and serves as a calibration camera, with its lens facing upward, to acquire images of the probe card and the upward-looking camera;

[0009] The overlooking camera includes a low-magnification lens and a low-magnification CCD for the overlooking camera for low-magnification, and a high-magnification lens and a high-magnification CCD for the overlooking camera for high-magnification, and also includes an overlooking camera lighting assembly; the overlooking camera lighting assembly provides lighting for the working environment of the overlooking camera;

[0010] The upward-looking camera includes an upward-looking camera low-magnification lens for low-magnification, an upward-looking camera high-magnification lens for high-magnification, an upward-looking camera CCD, a lens switching baffle, and an upward-looking camera lighting assembly; the upward-looking camera low-magnification lens and the upward-looking camera high-magnification lens share the upward-looking camera CCD, and the imaging lens is switched by the lens switching baffle; the upward-looking camera lighting assembly provides lighting for the upward-looking camera working environment;

[0011] There are crosshair marks on the lens surfaces of the downward-looking camera and the upward-looking camera, which are used as a reference when the downward-looking camera and the upward-looking camera are aimed at each other, and are also used to locate objects in the images collected by the downward-looking camera and the upward-looking camera.

[0012] Preferably, the wafer automatic needle alignment device also includes: a base, a No. 1 bracket, a No. 2 bracket, and a cover plate; the No. 1 bracket and the No. 2 bracket are both fixed on the upper surface of the base; the No. 1 bracket is connected to a fixed overhead camera; the probe card is fixed on the lower surface of the cover plate, and the No. 2 bracket is connected to the cover plate.

[0013] Preferably, the motion assembly includes a horizontal motion device; the horizontal motion device includes: an X-axis sliding plate, a Y-axis sliding plate, an X-axis linear motor for driving the X-axis sliding plate, a Y-axis linear motor for driving the Y-axis sliding plate, an X-axis grating ruler for X-axis positioning, and a Y-axis grating ruler for Y-axis positioning;

[0014] A Y-direction slide rail is provided on the upper surface of the base, a Y-direction slider matched with the Y-direction slide rail is provided on the lower surface of the Y-direction slide plate, and the Y-direction slide plate can slide in the Y direction by the cooperation between the Y-direction slide rail and the Y-direction slider; an X-direction slide rail is provided on the upper surface of the Y-direction slide plate, an X-direction slider matched with the X-direction slide rail is provided on the lower surface of the X-direction slide plate, and the X-direction slide plate can slide in the X direction by the cooperation between the X-direction slide rail and the X-direction slider; the scales of the X-direction linear motor and the X-direction grating ruler are both fixed on the upper surface of the Y-direction slide plate, and the sensor of the X-direction grating ruler is fixed on the lower surface of the X-direction slide plate; the scales of the Y-direction linear motor and the Y-direction grating ruler are both fixed on the upper surface of the base, and the sensor of the Y-direction grating ruler is fixed on the lower surface of the Y-direction slide plate.

[0015] Preferably, the motion assembly also includes a Z-direction motion device; the Z-direction motion device includes: a Z-direction base, a rotating element, and a Z-direction moving element; the Z-direction base is fixed to the upper surface of the X-direction sliding plate; the rotating element is connected and fixed to the Z-direction base, driving the wafer tray to rotate around its own central axis; the upper surface of the Z-direction moving element is connected and fixed to the wafer tray, and the lower surface is connected and fixed to the upper surface of the Z-direction base, driving the wafer tray to move in the Z direction.

[0016] Preferably, the motion component also includes an upward-looking camera supporting platform; the upward-looking camera supporting platform is fixed on the upper surface of the X-axis sliding plate, the upward-looking camera is connected and fixed to the upward-looking camera supporting platform, and the upward-looking camera supporting platform can move in the Z direction, driving the upward-looking camera to move in the Z direction.

[0017] Preferably, the Z-moving element comprises: a Z-moving plate, a Z-moving drive motor, a ball screw group, a driving toothed belt, a transmission toothed belt, a guide spline shaft group for limiting the moving direction of the Z-moving plate, and a Z-moving grating ruler for Z-positioning; the Z-moving drive motor is fixed on the upper surface of the Z-moving base; the screws of each ball screw constituting the ball screw group are perpendicular to the Z-moving base and connected and fixed, and the nuts are connected and fixed to the Z-moving plate; the shafts of each guide spline shaft constituting the guide spline shaft group are perpendicular to the Z-moving base and connected and fixed, and are connected to the Z-moving plate through splines; the output end of the Z-moving drive motor is connected to a motor gear, and each The ball screws are all connected with screw gears, and one ball screw is connected with a driving gear; the motor gear and the driving gear are meshed with the driving toothed belt, and all the screw gears are meshed with the transmission toothed belt; the Z-axis driving motor drives the driving toothed belt, which drives the driving gear, and the ball screw connected to the driving gear drives the other ball screws to move synchronously through the transmission toothed belt, thereby driving the Z-axis moving plate to move in the Z direction, and the guide spline shaft group guides the moving direction of the Z-axis moving plate to ensure that the moving direction of the Z-axis moving plate is perpendicular to the Z-axis base; the scale of the Z-axis grating ruler is perpendicular to the Z-axis base and is connected and fixed, and the sensor is connected and fixed to the Z-axis moving plate.

[0018] Preferably, the rotating element includes: a rotating drive motor, a rotating element screw, a rotating element base provided with a rotating element slide rail, a rotating element slider matched with the rotating element slide rail, and a rotating element connecting plate connected and fixed to the wafer tray; the rotating element base is fixed to the upper surface of the Z-direction base; the rotating drive motor is fixed to the rotating element base, and the rotating element screw is connected to the output end of the rotating drive motor; two driving rods are provided on the upper surface of the rotating element slider, and the rotating element connecting plate is placed between the two driving rods and abuts against the two driving rods; the rotating element slider is provided with a threaded hole, and the threaded hole matches with the rotating element screw; the rotating drive motor drives the rotating element screw to rotate, driving the rotating element slider to slide along the rotating element slide rail path, and the two driving rods on the rotating element slider drive the rotating element connecting plate and the wafer tray to rotate together.

[0019] Preferably, the upward-looking camera supporting platform includes: an upward-looking camera supporting platform base with an upward-looking camera supporting platform slide rail on the side, an upward-looking camera supporting platform driving motor, an upward-looking camera supporting platform ball screw, an upward-looking camera supporting platform sliding plate cooperating with the upward-looking camera supporting platform slide rail, and an upward-looking camera supporting platform grating ruler for Z-direction positioning of the upward-looking camera; the upward-looking camera supporting platform base is fixed on the upper surface of the X-direction sliding plate; the upward-looking camera is connected and fixed to the upward-looking camera supporting platform sliding plate; the upward-looking camera supporting platform driving motor is fixed on the upward-looking camera supporting platform base Surface; the screw of the ball screw of the upward-looking camera support platform is perpendicular to the base of the upward-looking camera support platform and is connected and fixed, and the nut is connected and fixed to the sliding plate of the upward-looking camera support platform; the upward-looking camera support platform driving motor drives the ball screw of the upward-looking camera support platform to rotate, drives the sliding plate of the upward-looking camera support platform to slide along the slide rail path of the upward-looking camera support platform, and then drives the upward-looking camera to move in the Z direction; the scale of the grating ruler of the upward-looking camera support platform is perpendicular to the base of the upward-looking camera support platform and is connected and fixed, and the sensor is connected and fixed to the sliding plate of the upward-looking camera support platform.

[0020] A wafer automatic needle alignment method comprises the following steps:

[0021] S1, adjust the horizontal motion device, move the wafer tray to the bottom of the overhead camera, adjust the Z motion device so that the image of the wafer to be aligned on the wafer tray is the clearest when observed by the overhead camera, and record the Z movement distance of the wafer tray at this time, which is recorded as Z1;

[0022] S2, adjust the horizontal motion device, move the upward camera to the bottom of the downward camera, adjust the camera support platform, make the image observed by the upward camera through the downward camera clearest, record the Z-direction moving distance of the upward camera at this time, and record it as Z2;

[0023] S3, measuring the height distance between the wafer to be aligned and the upward camera at this time, recorded as Z3, observing the needle on the probe card through the upward camera, calculating the Z-direction distance between the upward camera and the needle, recorded as Z4, and calculating the Z-direction distance between the wafer to be aligned and the needle through Z1-Z4, recorded as Z5;

[0024] S4, adjust the horizontal motion device so that the wafer tray enters the field of view of the downward camera, establish a horizontal coordinate system with the intersection of the main optical axis of the downward camera and the horizontal plane as the origin, calculate the center position of the wafer tray at this time (X1, Y1), adjust the horizontal motion device so that the upward camera enters the field of view of the downward camera, calculate the main optical axis position of the upward camera at this time (X2, Y2), the horizontal distance between the center of the wafer tray and the main optical axis of the upward camera is a fixed value, the X-direction distance is recorded as X3, and the Y-direction distance is recorded as Y3. The center position of the wafer tray at this time (X4, Y4) is obtained by calculation;

[0025] S5, adjusting the horizontal motion device so that the main optical axis of the upward camera is aligned with the needle on the probe card, recording the X-direction moving distance as X5, the Y-direction moving distance as Y5, and calculating the horizontal distance between the center of the wafer tray and the needle, recording the X-direction distance as X6, and the Y-direction distance as Y6;

[0026] S6, placing the wafer to be aligned on the upper surface of the wafer tray, determining the horizontal distance between the center of the wafer tray and the center of the wafer to be aligned by a top-down camera, the X-direction distance is recorded as X7, the Y-direction distance is recorded as Y7, the horizontal distance between the center of the wafer to be aligned and the needle is obtained by calculation, the X-direction distance is recorded as X8, the Y-direction distance is recorded as Y8, the horizontal distance between the pad point on the upper surface of the wafer and the needle is calculated by the given horizontal distances X9 and Y9 between the center of the wafer to be aligned and the pad point on the upper surface of the wafer, the X-direction distance is recorded as X10, the Y-direction distance is recorded as Y10;

[0027] S7. The data processing component controls the horizontal moving device and the Z-moving device to move using X10, Y10 and Z5 obtained through the above steps, so that the pad point on the upper surface of the wafer contacts the needle, completing the needle alignment.

[0028] The present invention can achieve the following technical effects:

[0029] (1) Wafer alignment is performed through image recognition and grating ruler positioning, and alignment in the X, Y and Z directions can be completed simultaneously;

[0030] (2) The equipment used is simple, using only two cameras and motion components for image acquisition, without the aid of calibration blocks, thus reducing the difficulty of installation and the steps of needle alignment;

[0031] (3) The alignment method is simple, data processing is more accurate, and alignment accuracy and efficiency are improved, providing a feasible method for realizing a fully automatic three-dimensional alignment wafer probe station. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a front view of a schematic structural diagram according to an embodiment of the present invention;

[0033] Figure 2 is a top view of a schematic structural diagram according to an embodiment of the present invention;

[0034] Figure 3 is a schematic diagram of a specific structure of a top-down camera according to an embodiment of the present invention;

[0035] Figure 4 is a schematic diagram of a specific structure of an upward-looking camera according to an embodiment of the present invention;

[0036] Figure 5 is a schematic diagram of a specific structure of a horizontal motion device according to an embodiment of the present invention;

[0037] Figure 6 It is a schematic diagram of the specific structure of the Z-axis motion device and the upward-looking camera support platform according to an embodiment of the present invention.

[0038] The reference numerals include: image acquisition component 1, motion component 2, wafer tray 3, probe card 4, base 5, bracket No. 1 6, bracket No. 2 7, cover plate 8, top-view camera 11, top-view camera 12, horizontal motion device 21, Z-direction motion device 22, top-view camera support platform 23, top-view camera low-magnification lens 111, top-view camera low-magnification CCD 112, top-view camera high-magnification lens 113, top-view camera high-magnification CCD 114, top-view camera lighting component 115, top-view camera low-magnification lens 121, top-view camera high-magnification lens 122, top-view camera CCD 123, lens switching baffle 124, top-view camera lighting component 125, X-direction sliding plate 211, Y-direction sliding plate 212, X-direction linear motor 213, Y-direction linear motor 214, X-direction grating ruler 215 , Y-axis grating ruler 216, X-axis slide rail 217, Y-axis slide rail 218, Z-axis base 221, Z-axis moving plate 2221, Z-axis drive motor 2222, ball screw group 2223, drive toothed belt 2224, transmission toothed belt 2225, guide spline shaft group 2226, Z-axis grating ruler 2227, rotation drive motor 2231, rotating element screw 2232, rotating element base 2233, rotating element slide rail 2234, rotating element slider 2235, rotating element connecting plate 2236, driving rod 2237, upward-looking camera support platform base 231, upward-looking camera support platform drive motor 232, upward-looking camera support platform ball screw 233, upward-looking camera support platform slide rail 234, upward-looking camera support platform sliding plate 235, upward-looking camera support platform grating ruler 236. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0040] like Figure 1As shown, the automatic wafer alignment device provided by the present invention includes an image acquisition component 1 composed of a camera with a crosshair mark on the lens surface, a motion component 2 that performs fixed-value movement through a grating ruler, a data processing component, a wafer tray 3 for carrying wafers to be aligned, and a probe card 4 for aligning the wafers to be aligned; the image acquisition component 1 acquires images of the wafer tray 3, the probe card 4 and the wafers to be aligned, and transmits the acquired images to the data processing component, and the data processing component determines the positions of the wafer tray 3, the probe card 4 and the wafers to be aligned by positioning through the crosshair mark based on the acquired images, and obtains their position coordinates; the wafer tray 3 is connected and fixed to the motion component 2, and the wafer tray 3 is driven to move by the motion component 2, and the various grating rulers of the motion component 2 are used to perform precise fixed-distance movement and accurate reading of the moving distance.

[0041] like Figure 2 As shown, in one embodiment of the present invention, the image acquisition component 1 includes: a downward-looking camera 11 and an upward-looking camera 12; the position of the downward-looking camera 11 is fixed and does not change, and it serves as a reference camera with its lens facing downward, for acquiring images of the wafer tray 3, the upward-looking camera 12 and the wafer to be aligned; the upward-looking camera 12 is connected and fixed to the motion component 2, and moves horizontally with the wafer tray 3, and serves as a calibration camera with its lens facing upward, for acquiring images of the probe card 4 and the upward-looking camera 12.

[0042] like Figure 3 As shown, the overhead camera 11 includes an overhead camera low-magnification lens 111 and an overhead camera low-magnification CCD 112, as well as an overhead camera high-magnification lens 113 and an overhead camera high-magnification CCD 114, and also includes an overhead camera lighting component 115; the overhead camera low-magnification lens 111 and the overhead camera low-magnification CCD 112 are used for low-magnification magnification, with a large field of view, and are applied to preliminary positioning, and move the image component to be collected to the collection position; the overhead camera high-magnification lens 113 and the overhead camera high-magnification CCD 114 are used for high-magnification magnification, with a small field of view, and are applied to precise positioning, and determine the position of the image component to be collected; the overhead camera lighting component 115 provides lighting to maintain the working environment of the overhead camera 11.

[0043] like Figure 4As shown, the upward-looking camera 12 includes an upward-looking camera low-magnification lens 121, an upward-looking camera high-magnification lens 122, an upward-looking camera CCD 123, a lens switching baffle 124, and an upward-looking camera lighting component 125; the upward-looking camera low-magnification lens 121 and the upward-looking camera high-magnification lens 122 share the upward-looking camera CCD 123, which can reduce the size of the upward-looking camera 12, and switch the imaging lens through the lens switching baffle 124; the upward-looking camera low-magnification lens 121 is used for low-magnification magnification, with a large field of view, and is used for preliminary positioning, and moves the upward-looking camera 12 to the collection position; the upward-looking camera high-magnification lens 122 is used for high-magnification magnification, with a small field of view, and is used for precise positioning, and determines the position of the image component to be collected; the upward-looking camera lighting component 125 provides lighting to maintain the working environment of the upward-looking camera 12.

[0044] There are crosshair marks on the lens surfaces of the downward-looking camera 11 and the upward-looking camera 12, which are used as a reference when the downward-looking camera 11 and the upward-looking camera 12 aim at each other. When the crosshair marks of the two camera lenses coincide, it is determined that the principal optical axes of the lenses of the two cameras coincide. It is also used to locate objects in the images captured by the downward-looking camera 11 and the upward-looking camera 12. The horizontal distance of the object in the image from the principal optical axis of the lens of the downward-looking camera 11 or the upward-looking camera 12 can be directly read according to the marks on the crosshair marks.

[0045] like Figure 1 As shown, in one embodiment of the present invention, it also includes a base 5, a No. 1 bracket 6, a No. 2 bracket 7, and a cover plate 8; the base 5 serves as a base to support the entire device; the No. 1 bracket 6 and the No. 2 bracket 7 are both fixed on the upper surface of the base 4; the No. 1 bracket 6 is connected to a fixed overhead camera 11 to keep the position of the overhead camera 11 fixed; the probe card 4 is fixed on the lower surface of the cover plate 8, and the No. 2 bracket 7 is connected to the cover plate 8 to keep the position of the probe card 4 fixed.

[0046] like Figure 2 As shown, in one embodiment of the present invention, the motion assembly 2 includes a horizontal motion device 21; Figure 5 As shown, the horizontal motion device 21 includes: an X-axis sliding plate 211, a Y-axis sliding plate 212, an X-axis linear motor 213 for driving the X-axis sliding plate 211, a Y-axis linear motor 214 for driving the Y-axis sliding plate 212, an X-axis grating ruler 215 for X-axis positioning, and a Y-axis grating ruler 216 for Y-axis positioning;

[0047] The upper surface of the base 4 is provided with a Y-direction slide rail 218, and the lower surface of the Y-direction slide plate 212 is provided with a Y-direction slider matched with the Y-direction slide rail 218, and the Y-direction slide plate 212 can slide in the Y direction through the cooperation between the Y-direction slide rail 218 and the Y-direction slider; the upper surface of the Y-direction slide plate 212 is provided with an X-direction slide rail 217, and the lower surface of the X-direction slide plate 211 is provided with an X-direction slider matched with the X-direction slide rail 217, and the X-direction slide plate 211 can slide in the X direction through the cooperation between the X-direction slide rail 217 and the X-direction slider; the X-direction linear motor 213 and the X-direction grating ruler 215 are fixed on the upper surface of the Y-direction slide plate 212, and the sensor of the X-direction grating ruler 215 The sensor is fixed on the lower surface of the X-axis sliding plate 211; the scales of the Y-axis linear motor 214 and the Y-axis grating ruler 216 are fixed on the upper surface of the base 4, and the sensor of the Y-axis grating ruler 216 is fixed on the lower surface of the Y-axis sliding plate 212; the Y-axis linear motor 214 drives the Y-axis sliding plate 212 to slide along the Y-axis slide rail 218, and performs precise Y-axis fixed-distance movement and accurate reading of the Y-axis moving distance through the Y-axis grating ruler 216; the X-axis linear motor 213 drives the X-axis sliding plate 211 to slide along the X-axis slide rail 217, and performs precise X-axis fixed-distance movement and accurate reading of the X-axis moving distance through the X-axis grating ruler 215.

[0048] like Figure 2 As shown, in one embodiment of the present invention, the motion assembly 2 further includes a Z-direction motion device 22; Figure 6 As shown, the Z-direction motion device 22 includes: a Z-direction base 221, a rotating element, and a Z-direction moving element; the Z-direction base 221 is fixed to the upper surface of the X-direction sliding plate 211; the rotating element is connected and fixed to the Z-direction base 221, driving the wafer tray 3 to rotate around its own central axis; the upper surface of the Z-direction moving element is connected and fixed to the wafer tray 3, and the lower surface is connected and fixed to the upper surface of the Z-direction base 211, driving the wafer tray 3 to move in the Z direction.

[0049] like Figure 6As shown, the Z-direction moving element includes: a Z-direction moving plate 2221, a Z-direction driving motor 2222, a ball screw group 2223, a driving toothed belt 2224, a transmission toothed belt 2225, a guide spline shaft group 2226 for limiting the moving direction of the Z-direction moving plate, and a Z-direction grating ruler 2227 for Z-direction positioning; the Z-direction driving motor 2222 is fixed on the upper surface of the Z-direction base 221; the screw of each ball screw constituting the ball screw group 2223 is perpendicular to the Z-direction base 221 and connected and fixed, and the nut is connected and fixed to the Z-direction moving plate 2221; the axis of each guide spline shaft constituting the guide spline shaft group 2226 is perpendicular to the Z-direction base 221 and connected and fixed, and is connected to the Z-direction moving plate 2221 through a spline; the output end of the Z-direction driving motor 2222 is connected to a motor gear, and each ball screw is connected to a screw gear, A ball screw is connected to a driving gear; the motor gear and the driving gear are meshed with the driving toothed belt 2224, and all the screw gears are meshed with the transmission toothed belt 2225; the Z-axis driving motor 2222 drives the driving toothed belt 2224, which drives the driving gear, and the ball screw connected to the driving gear drives the other ball screws to move synchronously through the transmission toothed belt 2225, thereby driving the Z-axis moving plate 2221 to move in the Z direction, and the guide spline shaft group 2226 guides the moving direction of the Z-axis moving plate 2221 to ensure that the moving direction of the Z-axis moving plate 2221 is perpendicular to the Z-axis base 221; the scale of the Z-axis grating ruler 2227 is perpendicular to the Z-axis base 221 and is connected and fixed, and the sensor is connected and fixed to the Z-axis moving plate 2221, and accurate Z-axis fixed-distance movement and accurate reading of the Z-axis moving distance are performed through the Z-axis grating ruler 2227.

[0050] like Figure 6As shown, the rotating element includes: a rotating drive motor 2231, a rotating element lead screw 2232, a rotating element base 2233 provided with a rotating element slide rail 2234, a rotating element slider 2235 matched with the rotating element slide rail 2234, and a rotating element connecting plate 2236 connected and fixed to the wafer tray 3; the rotating element base 2233 is fixed to the upper surface of the Z-direction base 221; the rotating drive motor 2231 is fixed to the rotating element base 2233, and the rotating element lead screw 2232 is connected to the output end of the rotating drive motor 2231; two driving rods 2237 are provided on the upper surface of the rotating element slider 2235, and the rotating element is connected to the wafer tray 3. The plate 2236 is placed between the two driving rods 2237 and abuts against the two driving rods 2237; the rotating element slider 2235 is provided with a threaded hole, which cooperates with the rotating element lead screw 2232; the rotating drive motor 2231 drives the rotating element lead screw 2232 to rotate, driving the rotating element slider 2235 to slide along the rotating element slide rail 2234 path, and the two driving rods 2237 on the rotating element slider 2235 drive the rotating element connecting plate 2236 and the wafer tray 3, converting the linear movement of the rotating element slider 2235 into rotation of the rotating element connecting plate 2236, driving the wafer tray 3 to rotate.

[0051] like Figure 2 As shown, in one embodiment of the present invention, the motion assembly 2 further includes an upward-looking camera support platform 23; Figure 6 As shown, the upward-looking camera support platform 23 is connected to the upward-looking camera 12 and fixed on the upper surface of the X-axis sliding plate 211, driving the upward-looking camera 12 and the wafer tray 3 to move horizontally together. The upward-looking camera support platform 23 can move in the Z direction, driving the upward-looking camera 12 to move in the Z direction.

[0052] like Figure 6As shown, the upward-looking camera support platform 23 includes: an upward-looking camera support platform base 231 with an upward-looking camera support platform slide rail 234 on the side, an upward-looking camera support platform drive motor 232, an upward-looking camera support platform ball screw 233, an upward-looking camera support platform sliding plate 235 cooperating with the upward-looking camera support platform slide rail 234, and an upward-looking camera support platform grating ruler 236 for Z-direction positioning of the upward-looking camera 12; the upward-looking camera support platform base 231 is fixed on the upper surface of the X-direction sliding plate 211; the upward-looking camera 12 is connected and fixed to the upward-looking camera support platform sliding plate 235; the upward-looking camera support platform drive motor 232 is fixed on the upper surface of the upward-looking camera support platform base 231; the screw of the upward-looking camera support platform ball screw 233 is vertical It is connected and fixed to the upward-looking camera supporting platform base 231, and the nut is connected and fixed to the upward-looking camera supporting platform sliding plate 235; the upward-looking camera supporting platform driving motor 232 drives the upward-looking camera supporting platform ball screw 233 to rotate, driving the upward-looking camera supporting platform sliding plate 235 to slide along the upward-looking camera supporting platform slide rail 234 path, thereby driving the upward-looking camera 12 to move in the Z direction; the scale of the upward-looking camera supporting platform grating ruler 236 is perpendicular to the upward-looking camera supporting platform base 231 and connected and fixed, the sensor is connected and fixed to the upward-looking camera supporting platform sliding plate 235, and the upward-looking camera 12 is accurately moved in the Z direction and the Z-direction moving distance of the upward-looking camera 12 is accurately read through the upward-looking camera supporting platform grating ruler 236.

[0053] Combine the following Figure 1 , 2 , 5, 6 describe the method part of the present invention in detail:

[0054] A wafer automatic needle alignment method comprises the following steps:

[0055] S1, adjust the horizontal motion device 21, move the wafer tray 3 to the position directly below the overhead camera 11, adjust the Z-direction motion device 22, so that the image of the wafer to be aligned on the wafer tray 3 observed by the overhead camera 11 is the clearest, and record the Z-direction moving distance of the wafer tray 3 at this time by the Z-direction grating ruler 2227, which is recorded as Z1;

[0056] S2, adjust the horizontal motion device 21, move the upward camera 12 to the position directly below the downward camera 11, adjust the upward camera support platform 23, so that the image observed by the upward camera 12 through the downward camera 11 is the clearest, and record the Z-direction moving distance of the upward camera 12 at this time through the upward camera support platform grating ruler 236, which is recorded as Z2;

[0057] S3, measuring the height distance between the wafer to be aligned and the upward camera 12 at this time by the upward camera carrier grating ruler 236, recorded as Z3, observing the needle on the probe card 4 by the upward camera 12, calculating the Z-direction distance between the upward camera and the needle, recorded as Z4, and calculating the Z-direction distance between the wafer to be aligned and the needle by Z1-Z4, recorded as Z5;

[0058] S4, adjust the horizontal motion device 21 to make the wafer tray 3 enter the field of view of the downward camera 11, establish a horizontal coordinate system with the intersection of the main optical axis of the downward camera 11 and the horizontal plane as the origin, calculate the center position (X1, Y1) of the wafer tray 3 at this time, adjust the horizontal motion device 21 to make the upward camera 12 enter the field of view of the downward camera 11, calculate the main optical axis position (X2, Y2) of the upward camera 12 at this time, the horizontal distance between the center of the wafer tray 3 and the main optical axis of the upward camera 12 is a fixed value, the X-direction distance is recorded as X3, and the Y-direction distance is recorded as Y3, and the center position (X4, Y4) of the wafer tray at this time is obtained by calculation;

[0059] S5, adjusting the horizontal motion device 21, aligning the main optical axis of the upward camera 12 with the needle on the probe card 4, recording the X-direction moving distance as X5 through the X-direction grating ruler 215, and recording the Y-direction moving distance as Y5 through the Y-direction grating ruler 216, and calculating the horizontal distance between the center of the wafer tray 3 and the needle, recording the X-direction distance as X6, and the Y-direction distance as Y6;

[0060] S6, placing the wafer to be aligned on the upper surface of the wafer tray 3, determining the horizontal distance between the center of the wafer tray 3 and the center of the wafer to be aligned by the overhead camera 11, the X-direction distance is recorded as X7, the Y-direction distance is recorded as Y7, the horizontal distance between the center of the wafer to be aligned and the needle is obtained by calculation, the X-direction distance is recorded as X8, the Y-direction distance is recorded as Y8, the horizontal distance between the pad point on the upper surface of the wafer and the needle is calculated by the given horizontal distances X9 and Y9 between the center of the wafer to be aligned and the pad point on the upper surface of the wafer, the X-direction distance is recorded as X10, and the Y-direction distance is recorded as Y10;

[0061] S7, the data processing component controls the horizontal moving device 21 and the Z-moving device 22 to move according to the X10, Y10 and Z5 obtained in the above steps, so that the pad point on the upper surface of the wafer contacts the needle, completing the needle alignment.

[0062] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0063] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. Those skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

[0064] The above specific implementations of the present invention do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A wafer automatic needle alignment device, characterized in that: include: An image acquisition component consisting of a camera with a crosshair mark on the lens surface, a motion component that measures the motion distance through a grating ruler, a data processing component, a wafer tray for carrying wafers to be aligned, and a probe card for aligning the wafers to be aligned; the image acquisition component is used to capture images of the wafer tray, the probe card and the wafers to be aligned, and transmit the images to the data processing component; the data processing component is used to process the received image data and calculate the alignment parameters based on the data; The wafer tray is connected and fixed to the motion component, and the wafer tray is driven to move by the motion component; The image acquisition component includes: a top-down camera and an upward-looking camera; the top-down camera is fixed and unchanged in position, and serves as a reference camera with its lens facing downward to acquire images of the wafer tray, the upward-looking camera, and the wafer to be aligned, and a horizontal coordinate system is established with the intersection of the main optical axis of the top-down camera and the horizontal plane as the origin; the upward-looking camera is connected and fixed to the motion component, and moves horizontally with the wafer tray, and serves as a calibration camera with its lens facing upward to acquire images of the probe card and the upward-looking camera; The overhead camera includes an overhead camera low-magnification lens and an overhead camera low-magnification CCD for low-magnification, and an overhead camera high-magnification lens and an overhead camera high-magnification CCD for high-magnification, and also includes an overhead camera lighting assembly; the overhead camera lighting assembly provides lighting for the working environment of the overhead camera; The upward-looking camera comprises an upward-looking camera low-magnification lens for low-magnification, an upward-looking camera high-magnification lens for high-magnification, an upward-looking camera CCD, a lens switching baffle, and an upward-looking camera lighting assembly; the upward-looking camera low-magnification lens and the upward-looking camera high-magnification lens share the upward-looking camera CCD, and the imaging lens is switched by the lens switching baffle; the upward-looking camera lighting assembly provides lighting for the upward-looking camera working environment; The lens surfaces of the downward-looking camera and the upward-looking camera are both provided with crosshair marks, which are used as a reference when the downward-looking camera and the upward-looking camera aim at each other, and are also used to locate objects in the images captured by the downward-looking camera and the upward-looking camera; The motion assembly includes a horizontal motion device; the horizontal motion device includes: an X-axis sliding plate, a Y-axis sliding plate, an X-axis linear motor for driving the X-axis sliding plate, a Y-axis linear motor for driving the Y-axis sliding plate, an X-axis grating ruler for X-axis positioning, and a Y-axis grating ruler for Y-axis positioning; It also includes a base, wherein the upper surface of the base is provided with a Y-direction slide rail, the lower surface of the Y-direction slide plate is provided with a Y-direction slider matched with the Y-direction slide rail, and the Y-direction slide plate can slide in the Y direction through the cooperation between the Y-direction slide rail and the Y-direction slider; the upper surface of the Y-direction slide plate is provided with an X-direction slide rail, and the lower surface of the X-direction slide plate is provided with an X-direction slider matched with the X-direction slide rail, and the X-direction slide plate can slide in the X direction through the cooperation between the X-direction slide rail and the X-direction slider; the X-direction linear motor and the scale of the X-direction grating ruler are both fixed on the upper surface of the Y-direction slide plate, and the sensor of the X-direction grating ruler is fixed on the lower surface of the X-direction slide plate ; The scales of the Y-axis linear motor and the Y-axis grating ruler are both fixed on the upper surface of the base, and the sensor of the Y-axis grating ruler is fixed on the lower surface of the Y-axis sliding plate; the motion assembly also includes a Z-axis motion device; the Z-axis motion device includes: a Z-axis base, a rotating element, and a Z-axis moving element; the Z-axis base is fixed to the upper surface of the X-axis sliding plate; the rotating element is connected and fixed to the Z-axis base, driving the wafer tray to rotate around its own central axis; the upper surface of the Z-axis moving element is connected and fixed to the wafer tray, and the lower surface is connected and fixed to the upper surface of the Z-axis base, driving the wafer tray to move in the Z direction.

2. The wafer automatic needle alignment device according to claim 1, characterized in that: Also includes: A No. 1 bracket, a No. 2 bracket, and a cover plate; the No. 1 bracket and the No. 2 bracket are both fixed to the upper surface of the base; The first bracket is connected to fix the top-view camera; The probe card is fixed on the lower surface of the cover plate, and the second bracket is connected to the cover plate.

3. The wafer automatic needle alignment device according to claim 1, characterized in that: The motion component also includes an upward-looking camera supporting platform; the upward-looking camera supporting platform is fixed to the upper surface of the X-axis sliding plate, the upward-looking camera is connected and fixed to the upward-looking camera supporting platform, and the upward-looking camera supporting platform can move in the Z direction, driving the upward-looking camera to move in the Z direction.

4. The wafer automatic needle alignment device according to claim 1, characterized in that: The Z-axis moving element includes: a Z-axis moving plate, a Z-axis driving motor, a ball screw group, a driving toothed belt, a transmission toothed belt, a guide spline shaft group for limiting the moving direction of the Z-axis moving plate, and a Z-axis grating ruler for Z-axis positioning; the Z-axis driving motor is fixed on the upper surface of the Z-axis base; the screw of each ball screw constituting the ball screw group is perpendicular to the Z-axis base and connected and fixed, and the nut is connected and fixed to the Z-axis moving plate; the axis of each guide spline shaft constituting the guide spline shaft group is perpendicular to the Z-axis base and connected and fixed, and is connected to the Z-axis moving plate through a spline; the output end of the Z-axis driving motor is connected to a motor gear, and each of the ball screws is connected to a screw gear Wheel, one of the ball screws is connected with a driving gear; the motor gear and the driving gear are meshed with the driving toothed belt, and all the screw gears are meshed with the transmission toothed belt; the Z-axis driving motor drives the driving toothed belt to drive the driving gear, and the ball screw connected to the driving gear drives the remaining ball screws to move synchronously through the transmission toothed belt, thereby driving the Z-axis moving plate to move in the Z direction, and the guide spline shaft group guides the moving direction of the Z-axis moving plate to ensure that the moving direction of the Z-axis moving plate is perpendicular to the Z-axis base; the scale of the Z-axis grating ruler is perpendicular to the Z-axis base and is connected and fixed, and the sensor is connected and fixed to the Z-axis moving plate.

5. The wafer automatic needle alignment device according to claim 1, characterized in that: The rotating element includes: a rotating drive motor, a rotating element screw, a rotating element base provided with a rotating element slide rail, a rotating element slider matched with the rotating element slide rail, and a rotating element connecting plate connected and fixed to the wafer tray; the rotating element base is fixed to the upper surface of the Z-direction base; the rotating drive motor is fixed to the rotating element base, and the rotating element screw is connected to the output end of the rotating drive motor; two driving rods are provided on the upper surface of the rotating element slider, and the rotating element connecting plate is placed between the two driving rods and abuts against the two driving rods; the rotating element slider is provided with a threaded hole, and the threaded hole matches with the rotating element screw; the rotating drive motor drives the rotating element screw to rotate, driving the rotating element slider to slide along the rotating element slide rail path, and the two driving rods on the rotating element slider drive the rotating element connecting plate and the wafer tray to rotate together.

6. The wafer automatic needle alignment device according to claim 1 or 3, characterized in that: The upward-looking camera support platform includes: an upward-looking camera support platform base with an upward-looking camera support platform slide rail on the side, an upward-looking camera support platform drive motor, an upward-looking camera support platform ball screw, an upward-looking camera support platform sliding plate matched with the upward-looking camera support platform slide rail, and an upward-looking camera support platform grating ruler for Z-direction positioning of the upward-looking camera; the upward-looking camera support platform base is fixed on the upper surface of the X-direction sliding plate; the upward-looking camera is connected and fixed to the upward-looking camera support platform sliding plate; the upward-looking camera support platform drive motor is fixed on the upper surface of the upward-looking camera support platform base; The lead screw of the ball screw of the upward-looking camera support platform is perpendicular to the base of the upward-looking camera support platform and is connected and fixed, and the nut is connected and fixed to the sliding plate of the upward-looking camera support platform; the upward-looking camera support platform driving motor drives the ball screw of the upward-looking camera support platform to rotate, drives the sliding plate of the upward-looking camera support platform to slide along the slide rail path of the upward-looking camera support platform, and then drives the upward-looking camera to move in the Z direction; the scale of the grating ruler of the upward-looking camera support platform is perpendicular to the base of the upward-looking camera support platform and is connected and fixed, and the sensor is connected and fixed to the sliding plate of the upward-looking camera support platform.

7. A wafer automatic needle alignment method, characterized in that: The following steps are involved: S1, adjust the horizontal motion device, move the wafer tray to the bottom of the overhead camera, adjust the Z motion device so that the image of the wafer to be aligned on the wafer tray is the clearest when observed by the overhead camera, and record the Z movement distance of the wafer tray at this time, which is recorded as Z1; S2, adjust the horizontal motion device, move the upward camera to the bottom of the downward camera, adjust the upward camera support platform, so that the image observed by the upward camera through the downward camera is the clearest, and record the Z-direction movement distance of the upward camera at this time, which is recorded as Z2; S3, measuring the height distance between the wafer to be aligned and the upward camera at this time, recorded as Z3, observing the needle on the probe card through the upward camera, calculating the Z-direction distance between the upward camera and the needle, recorded as Z4, and calculating the Z-direction distance between the wafer to be aligned and the needle through Z1-Z4, recorded as Z5; S4, adjust the horizontal motion device so that the wafer tray enters the field of view of the downward camera, establish a horizontal coordinate system with the intersection of the main optical axis of the downward camera and the horizontal plane as the origin, calculate the center position of the wafer tray at this time (X1, Y1), adjust the horizontal motion device so that the upward camera enters the field of view of the downward camera, calculate the main optical axis position of the upward camera at this time (X2, Y2), the horizontal distance between the center of the wafer tray and the main optical axis of the upward camera is a fixed value, the X-direction distance is recorded as X3, and the Y-direction distance is recorded as Y3. The center position of the wafer tray at this time (X4, Y4) is obtained by calculation; S5, adjusting the horizontal motion device so that the main optical axis of the upward camera is aligned with the needle on the probe card, recording the X-direction moving distance as X5, the Y-direction moving distance as Y5, and calculating the horizontal distance between the center of the wafer tray and the needle, recording the X-direction distance as X6, and the Y-direction distance as Y6; S6, placing the wafer to be aligned on the upper surface of the wafer tray, determining the horizontal distance between the center of the wafer tray and the center of the wafer to be aligned by a top-down camera, the X-direction distance is recorded as X7, the Y-direction distance is recorded as Y7, the horizontal distance between the center of the wafer to be aligned and the needle is obtained by calculation, the X-direction distance is recorded as X8, the Y-direction distance is recorded as Y8, the horizontal distance between the pad point on the upper surface of the wafer and the needle is calculated by the given horizontal distances X9 and Y9 between the center of the wafer to be aligned and the pad point on the upper surface of the wafer, the X-direction distance is recorded as X10, the Y-direction distance is recorded as Y10; S7, the data processing component controls the horizontal moving device and the Z-moving device to move by using X10, Y10 and Z5 obtained through the above steps, so that the pad point on the upper surface of the wafer contacts the needle, completing the needle alignment.

Images