A wafer testing device

Abstract

The invention discloses a wafer testing device, comprising a workbench, a distance measuring mechanism, a thickness measuring mechanism and an adsorption mechanism, wherein the surface of the workbench is provided with ventilation holes and two circle center positioning plates arranged in a V shape; the distance measuring mechanism comprises two distance sensors arranged to rotate oppositely; the thickness measuring mechanism comprises a power mechanism, a slider slidably installed above the workbench and a turntable rotatably installed below the slider, wherein the axis of horizontal movement of the slider is oppositely parallel to the V-shaped bisector of the two circle center positioning plates below, a plurality of guide rods are arranged in an annular array on the bottom surface of the turntable, a plurality of distance sensors arranged at equal intervals are connected to the bottom of the guide rods through a telescopic assembly, and the power mechanism can synchronously drive the distance between two adjacent distance sensors installed on the same telescopic assembly to change at equal intervals; the adsorption mechanism comprises an adsorption block having an air suction cavity arranged on the top surface and connected to an air suction machine, wherein the air suction cavity can be opposite to the local ventilation hole, and the invention improves the testing efficiency of the wafer as a whole.

Description

Technical Field

[0001] The present invention relates to the technical field of testing devices, and particularly to a wafer testing device. Background Art

[0002] A wafer is a basic material for manufacturing semiconductor devices. High-purity polysilicon is formed into a cylindrical single crystal silicon through crystal pulling. The wafer goes through a series of manufacturing processes to form extremely tiny circuit structures, and then becomes a chip through processes such as cutting, packaging, and testing, and is widely applied to various electronic devices. In the process flow of wafer processing, it is necessary to perform rounding processing on the edge of the wafer obtained by slicing so that its edge can form a certain contour shape to improve the mechanical strength and processability of the wafer. At the same time, it is necessary to grind the diameter of the wafer to a specific size. Similarly, it is also necessary to perform planarization processing on the surface of the wafer and perform a certain amount of thinning so that its thickness and flatness meet the requirements. Therefore, it is necessary to detect size parameters such as the diameter and thickness of the wafer.

[0003] However, the existing devices for testing the size of wafers have the following defects:

[0004] (1) During the testing process of the wafer, it is necessary to locate the center of the wafer. Manual positioning has low accuracy, is time-consuming and laborious, and it is necessary to use a clamping device to fix the wafer to prevent the wafer from moving during the testing process. However, the wafer is easily worn during the clamping process.

[0005] (2) Some devices adjust the position points of the distance sensors for detecting the thickness of the wafer by moving the connecting rod. On the one hand, it is difficult for the device to be applicable to the testing of wafers of various sizes. On the other hand, the position points detected by the distance sensors are unevenly distributed, resulting in a decrease in the detection accuracy. Therefore, the efficiency of wafer testing in the prior art is low. Summary of the Invention

[0006] For this reason, the present invention provides a wafer testing device to solve the above defects in the prior art.

[0007] A wafer testing device includes:

[0008] A workbench, on the surface of which there are two center positioning plates arranged in a V shape, and there are also a number of ventilation holes evenly distributed on the surface of the workbench;

[0009] A ranging mechanism, which includes a first distance sensor and a second distance sensor that are oppositely arranged and can rotate in a horizontal plane around the midpoint of their connection line. Both the first distance sensor and the second distance sensor are connected to the same controller;

[0010] The thickness measuring mechanism comprises a power mechanism, a support plate installed above the workbench, a slider installed horizontally on the support plate, and a rotating plate installed rotatably below the slider, wherein the axis of the horizontal movement of the slider is vertically parallel to the V-shaped bisector of the two center positioning plates below, a plurality of guide rods are arranged in an annular array on the bottom surface of the rotating plate, and a plurality of third distance sensors arranged equidistantly are connected to the lower side of the guide rods through a telescopic assembly, and the power mechanism can synchronously drive the distance between two adjacent third distance sensors installed on the same telescopic assembly to change equidistantly;

[0011] The adsorption mechanism comprises a detachable adsorption block adsorbed under the workbench, the top surface of the adsorption block is provided with an air suction cavity, the air suction cavity can be directly opposite to the local air vent, and the air suction cavity is connected to the air suction machine through an air suction pipe.

[0012] Preferably, the height of the center positioning plate is smaller than the thickness of the wafer on the workbench.

[0013] Preferably, a first motor is installed at the center of the bottom surface of the workbench, a rotating arm is installed on the rotating shaft of the first motor, the rotating shaft is connected to the center of the rotating arm, the first distance sensor and the second distance sensor are connected to both ends of the rotating arm, and the first motor is connected to the controller.

[0014] Preferably, a threaded rod is installed horizontally and rotatably below the support plate, one end of the threaded rod is driven to rotate by a second motor, the second motor is connected to the controller, the slider is mounted on the threaded rod through a lead screw nut, and a horizontal guide rail is provided below the support plate parallel to the threaded rod to provide guidance for the slider.

[0015] Preferably, the power mechanism includes a vertical guide cylinder rotatably installed under the slider, the rotating disk is installed under the vertical guide cylinder, a guide block is vertically slidably arranged inside the vertical guide cylinder, a lifting cylinder is vertically installed on the slider, a give way groove penetrating the lifting cylinder is provided on the support plate, the lower end push rod of the lifting cylinder is movably installed on the guide block, the lower section side wall of the guide block is constructed as an arc guide rail that shrinks inward from top to bottom, and a plurality of guide grooves are provided on the rotating disk to provide guidance for the movement of the guide rod, the inner end of the guide rod is pressed against the side wall of the arc guide rail by a guide wheel, the inner side of the guide rod and the inner side of the guide groove are connected by a reset spring, and the two ends of the telescopic assembly are connected to the side wall of the guide groove and the distal end of the guide rod.

[0016] Preferably, the top end of the vertical guide cylinder is mounted on the lower surface of the sliding block via a bearing.

[0017] Preferably, the telescopic assembly includes a first link group and a second link group arranged crosswise to the first link group. The first link group includes a plurality of first links parallel to each other, and the second link group includes a plurality of second links parallel to each other and arranged crosswise to the first links. The intersections of the first links and the second links are hinged, and the third distance sensor is installed at the hinged part of the first links and the second links. The first links and the second links are connected to each other to form a parallelogram telescopic structure.

[0018] Preferably, a toothed ring is provided on the side wall of the vertical guide cylinder. One side of the toothed ring is provided with a gear meshing with the toothed ring. The gear is driven to rotate by a third motor installed on the slider, and the third motor is connected to the controller.

[0019] The present invention has the following advantages:

[0020] Through the cooperation among the workbench, the distance measuring mechanism, the thickness measuring mechanism and the adsorption mechanism, the present invention first places the wafer on the workbench, limits the straight line passed by the center of the wafer, and adsorbs the lower part of the wafer through the adsorption mechanism to prevent the wafer from moving; measures the radius and roundness parameters of the wafer by rotating two oppositely arranged distance sensors, calculates the coordinates of the center of the wafer, and drives the thickness measuring mechanism to move to directly above the center of the wafer, adjusts the distance of the distance sensor for measuring thickness to adapt to the size of the wafer diameter, so that the measuring points for thickness measurement are relatively evenly distributed, improving the accuracy of wafer thickness measurement and overall improving the test efficiency of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 is a schematic diagram of the partial sectional structure of the present invention;

[0023] Figure 3 is of Figure 2 the enlarged structural schematic diagram of part A in the present invention;

[0024] Figure 4 is a schematic diagram of the top surface structure of the distance measuring mechanism of the present invention;

[0025] Figure 5 is a schematic diagram of the structures of the adsorption mechanism and the back of the distance measuring mechanism of the present invention.

[0026] In the figure:

[0027] 1 - workbench; 2 - distance measuring mechanism; 3 - controller; 4 - adsorption mechanism; 10 - wafer;

[0028] 101 - center positioning plate; 102 - vent hole;

[0029] 201-first motor; 202-rotating shaft; 203-rotating arm; 204-first distance sensor; 205-second distance sensor; 206-controller;

[0030] 301-support plate; 302-slider; 303-lifting cylinder; 304-second motor; 305-threaded rod; 306-screw nut; 307-horizontal guide rail; 308-third distance sensor; 309-guide block; 310-vertical guide cylinder; 311-arc guide rail; 312-guide wheel; 313-guide rod; 314-guide groove; 315-telescopic assembly; 316-third motor; 317-gear; 318-gear ring; 319-turntable; 320-reset spring; 321-gap groove; 322-bearing;

[0031] 401-adsorption block; 402-intake pipe; 403-intake machine. DETAILED DESCRIPTION

[0032] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0033] like Figures 1 to 5 As shown, the present invention provides a wafer testing device, including a workbench 1, a distance measuring mechanism 2, a thickness measuring mechanism 3 and an adsorption mechanism 4.

[0034] The surface of the workbench 1 is provided with two center positioning plates 101 arranged in a V-shape, and the surface of the workbench 1 is also evenly distributed with a plurality of ventilation holes 102;

[0035] The distance measuring mechanism 2 includes a first distance sensor 204 and a second distance sensor 205 which are arranged opposite to each other and can rotate in a horizontal plane along the midpoint of the line connecting the first distance sensor 204 and the second distance sensor 205. Specifically:

[0036] A first motor 201 is installed at the center of the bottom surface of the workbench 1, a rotating arm 203 is installed on the rotating shaft 202 of the first motor 201, the rotating shaft 202 is connected to the center of the rotating arm 203, the first distance sensor 204 and the second distance sensor 205 are connected to the two ends of the rotating arm 203, and the first motor 201 is connected to the controller 206.

[0037] The first distance sensor 204 and the second distance sensor 205 are both connected to the same controller 206;

[0038] The height of the center positioning plate 101 is less than the thickness of the wafer 10 on the workbench 1, so that the center positioning plate 101 will not interfere with the measurement of the side wall of the wafer 10 by the first distance sensor 204 and the second distance sensor 205.

[0039] Among them, the thickness measuring mechanism 3 includes a power mechanism, a support plate 301 installed above the workbench 1, a slider 302 horizontally slidably installed on the support plate 301, and a mounting turntable 319 rotatably installed below the slider 302. The axis of the horizontal movement of the slider 302 is vertically and directly parallel to the bisector of the V shape formed by the two center positioning plates 101 below, so that the slider 302 can move upward along the diameter direction passing through the center of the wafer 10. Specifically:

[0040] A threaded rod 305 is horizontally and rotatably installed below the support plate 301. One end of the threaded rod 305 is driven to rotate by a second motor 304. The second motor 304 is connected to the controller 206. The slider 302 is sleeved on the threaded rod 305 through a lead screw nut 306. A horizontal guide rail 307 for guiding the slider 302 is arranged below the support plate 301 in parallel with the threaded rod 305.

[0041] A plurality of guide rods 313 are annularly arranged on the bottom surface of the mounting turntable 319. The lower part of the guide rod 313 is connected with a plurality of third distance sensors 308 arranged at equal intervals through a telescopic assembly 315. Specifically:

[0042] The telescopic assembly 315 includes a first link group and a second link group arranged crosswise with the first link group. The first link group includes a plurality of parallel first links. The second link group includes a plurality of parallel second links arranged crosswise with the first links. The intersection of the first link and the second link is hinged. The third distance sensor 308 is installed at the hinged part of the first link and the second link. The first link and the second link are connected to form a parallelogram telescopic structure.

[0043] The power mechanism can synchronously drive the equal-distance change of the distance between two adjacent third distance sensors 308 installed on the same telescopic assembly 315. Specifically:

[0044] The power mechanism includes a vertical guide cylinder 310 rotatably installed below the slider 302, and the top end of the vertical guide cylinder 310 is installed on the lower surface of the slider 302 through a bearing 322. The installation turntable 319 is installed below the vertical guide cylinder 310. A guide block 309 is vertically slidably arranged inside the vertical guide cylinder 310. A lifting cylinder 303 is vertically installed on the slider 302. A relief groove 321 passing through the lifting cylinder 303 is formed on the support plate 301. The lower end push rod of the lifting cylinder 303 is movably installed on the guide block 309. The side wall of the lower section of the guide block 309 is configured as an arc-shaped guide rail 311 that contracts inward from top to bottom. A number of guide grooves 314 for guiding the movement of the guide rods 313 are formed on the installation turntable 319. The inner end of the guide rod 313 is pressed against the side wall of the arc-shaped guide rail 311 through a guide wheel 312. A return spring 320 is connected between the inner side of the guide rod 313 and the inner side of the guide groove 314. Both ends of the telescopic assembly 315 are connected to the side wall of the guide groove 314 and the distal end of the guide rod 313.

[0045] In order to enable the third distance sensor 308 to have more measurement points and improve the measurement accuracy. A toothed ring 318 is arranged on the side wall of the vertical guide cylinder 310. A gear 317 meshing with the toothed ring 318 is arranged on one side of the toothed ring 318. The gear 317 is driven to rotate by a third motor 316 installed on the slider 302, and the third motor 316 is connected to the controller 206.

[0046] Among them, the adsorption mechanism 4 includes an adsorption block 401 detachably adsorbed below the workbench 1. An air suction cavity (not shown in the figure) is arranged on the top surface of the adsorption block 401. The air suction cavity can be directly opposite to a part of the ventilation holes 102. The air suction cavity is connected to an air suction machine 403 through an air suction pipe 402.

[0047] The working principle of the device of the present invention is as follows:

[0048] I. Loading:

[0049] Place the wafer 10 on the workbench 1, and make the two side walls of the wafer 10 tangent to two center positioning plates 101 arranged in a V-shaped angle on the workbench 1. Thus, the center of the wafer 10 can fall on a predetermined axis.

[0050] Then move the adsorption block 401 to a position directly opposite to the wafer 10 below the workbench 1. Start the air suction machine 403. Through the air suction pipe 402, a negative pressure is generated in the ventilation holes 102 below the wafer 10 communicated with the air suction cavity, so as to adsorb the wafer 10 on the surface of the workbench 1 and prevent the wafer 10 from moving randomly.

[0051] II. Wafer Roundness Detection and Center Determination:

[0052] The first distance sensor 204 and the second distance sensor 205 arranged opposite to each other measure the distances between them and the outer wall of the wafer 10. Then, the first motor 201 is started, and the rotating shaft 202 of the first motor 201 drives the rotating arm 203 to rotate. The first distance sensor 204 and the second distance sensor 205 installed at both ends of the rotating arm 203 rotate with the rotating arm 203 by a certain angle and then measure the distances between them and the corresponding side walls of the wafer 10 again.

[0053] The controller 206 can judge parameters such as the roundness of the wafer 10, calculate the radius of the wafer 10, etc., based on the values measured by the first distance sensor 204 and the second distance sensor 205 multiple times, and calculate the center coordinates of the wafer 10.

[0054] III. Wafer Thickness Detection:

[0055] After that, the controller 206 commands the second motor 304 to work. Since the second motor 304 drives the slider 302 to move horizontally to directly above the center of the wafer 10 on the workbench 1. Specifically:

[0056] The second motor 304 drives the threaded rod 305 to rotate, and the slider 302 sleeved on the threaded rod 305 through the lead screw nut 306 slides horizontally under the guiding action of the horizontal guiding rail 307 until it slides to directly above the center of the wafer 10, and the slider 302 stops moving. At this time, the distance between each third distance sensor 308 for measuring the thickness of the wafer 10 is adjusted according to the diameter of the wafer 10. Specifically:

[0057] The ejector rod of the lifting cylinder 303 is driven to descend. The guiding block 309 installed at the lower end of the lifting cylinder 303 will descend vertically under the guiding action of the vertical guiding cylinder 310. The arc-shaped guiding rail 311 arranged on the lower side wall of the guiding block 309 will squeeze the guiding rod 313 connected to one side of the guiding wheel 312 during the downward movement, and the return spring 320 will be in a compressed state. During the process of the guiding rod 313 moving out along the guiding groove 314, the length of the telescopic assembly 315 increases, and the distances between each third distance sensor 308 equidistantly installed on the telescopic assembly 315 increase equidistantly, and the outermost third distance sensor 308 is directly opposite to the outer edge part of the wafer 10 below. The distance from the third distance sensor 308 to the surface of the wafer 10 below is detected. And the thickness of each part of the wafer 10 is calculated based on the difference between its height and the surface height of the workbench 1.

[0058] After collecting data, the third motor 316 drives the gear 317 to rotate. The gear 317 drives the vertical guide cylinder 310 where the meshing gear ring 318 is located to rotate. The mounting turntable 319 below the vertical guide cylinder 310 rotates by a certain angle around its center, so that the third distance sensor 308 can measure the surface thickness of more wafers 10 after rotation, improving the accuracy of data collection.

[0059] When the thickness measurement is completed, the lifting cylinder 303 resets. Under the elastic force of the reset spring 320, each third distance sensor 308 returns to the initial contracted state.

[0060] Through the cooperation among the workbench 1, the distance measuring mechanism 2, the thickness measuring mechanism 3 and the adsorption mechanism 4, the present invention first places the wafer 10 on the workbench 1, limits the straight line passed by the center of the wafer 10, and adsorbs the lower part of the wafer 10 through the adsorption mechanism 4 to prevent the wafer from moving; measures the radius and roundness parameters of the wafer by rotating two oppositely arranged distance sensors, calculates the coordinates of the center of the wafer, and drives the thickness measuring mechanism 3 to move directly above the center of the wafer 10, adjusts the distance of the distance sensor for measuring thickness to adapt to the size of the wafer diameter, so that the measurement points of the thickness are relatively evenly distributed, improving the accuracy of the wafer thickness measurement and overall improving the test efficiency of the wafer.

[0061] Although the present invention has been described in detail above with general descriptions and specific embodiments, on the basis of the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope claimed by the present invention.

Claims

1. A wafer testing device, characterized in that: It includes a workbench (1), on the surface of the workbench (1), there are two center positioning plates (101) arranged in a V shape, and on the surface of the workbench (1), there are also a number of ventilation holes (102) evenly distributed; a ranging mechanism (2), which includes a first distance sensor (204) and a second distance sensor (205) that are oppositely arranged and can rotate horizontally around the midpoint of their connection line. The first distance sensor (204) and the second distance sensor (205) are both connected to the same controller (206). At the center of the bottom surface of the workbench (1), a first motor (201) is installed. On the rotating shaft (202) of the first motor (201), a rotating arm (203) is installed. The rotating shaft (202) is connected to the center of the rotating arm (203). The first distance sensor (204) and the second distance sensor (205) are connected to both ends of the rotating arm (203), and the first motor (201) is connected to the controller (206); a thickness measuring mechanism (3), which includes a power mechanism, a support plate (301) installed above the workbench (1), a slider (302) horizontally slidably installed on the support plate (301), and a mounting turntable (319) rotatably installed below the slider (302). The axis of the horizontal movement of the slider (302) is vertically and directly parallel to the bisector of the V shape formed by the two center positioning plates (101) below. On the bottom surface of the mounting turntable (319), a number of guide rods (313) are arranged in an annular array. Below the guide rods (313), a number of third distance sensors (308) are connected at equal intervals through a telescopic assembly (315). The power mechanism can synchronously drive the distance between adjacent two of the third distance sensors (308) installed on the same telescopic assembly (315) to change at equal intervals; an adsorption mechanism (4), which includes an adsorption block (401) detachably adsorbed below the workbench (1). On the top surface of the adsorption block (401), there is an air suction cavity, and the air suction cavity can be directly opposite to a part of the ventilation holes (102). The air suction cavity is connected to an air suction machine (403) through an air suction pipe (402).

2. The wafer testing device according to claim 1, characterized in that: The height of the center positioning plate (101) is less than the thickness of the wafer (10) on the workbench (1).

3. The wafer testing device according to claim 1, characterized in that: A threaded rod (305) is horizontally rotatably installed below the support plate (301). One end of the threaded rod (305) is driven to rotate by a second motor (304). The second motor (304) is connected to the controller (206). The slider (302) is sleeved on the threaded rod (305) through a lead screw nut (306). Below the support plate (301), a horizontal guide rail (307) for guiding the slider (302) is arranged parallel to the threaded rod (305).

4. The wafer testing device according to claim 1, Features: The power mechanism comprises a vertical guide cylinder (310) rotatably mounted below the slider (302); the rotating disk (319) is mounted below the vertical guide cylinder (310); a guide block (309) is vertically slidably arranged inside the vertical guide cylinder (310); a lifting cylinder (303) is vertically mounted on the slider (302); a clearance groove (321) penetrating the lifting cylinder (303) is provided on the support plate (301); a lower end push rod of the lifting cylinder (303) is movably mounted on the guide block (309); and the guide block (309) is provided with a guide block (309). The side wall of the lower section is constructed as an arc-shaped guide rail (311) that contracts inward from top to bottom. The rotating disk (319) is provided with a plurality of guide grooves (314) that provide guidance for the movement of the guide rod (313). The inner end of the guide rod (313) is pressed against the side wall of the arc-shaped guide rail (311) through a guide wheel (312). The inner side of the guide rod (313) and the inner side of the guide groove (314) are connected through a return spring (320). The two ends of the telescopic assembly (315) are connected to the side wall of the guide groove (314) and the distal end of the guide rod (313).

5. The wafer testing device according to claim 4, Features: The top end of the vertical guide cylinder (310) is mounted on the lower surface of the sliding block (302) via a bearing (322).

6. A wafer testing device according to claim 1 or 4, Features: The telescopic assembly (315) includes a first link group and a second link group arranged crosswise with the first link group, the first link group includes a plurality of first links parallel to each other, the second link group includes a plurality of second links parallel to each other and arranged crosswise with the first link, the first link and the second link are hinged at the intersection, the third distance sensor (308) is installed at the hinge portion between the first link and the second link, and the first link and the second link are connected to each other to form a parallelogram telescopic structure.

7. The wafer testing device according to claim 4, Features: A gear ring (318) is disposed on the side wall of the vertical guide cylinder (310), and a gear (317) meshing with the gear ring (318) is disposed on one side of the gear ring (318), and the gear (317) is driven to rotate by a third motor (316) mounted on the slider (302), and the third motor (316) is connected to the controller (206).

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