TWM590775U - Wafer-placing status detection system - Google Patents

Abstract

A wafer placement state detection system includes at least one wafer cassette, a setting device, and an image capture device, the wafer cassette is used to store a plurality of wafers, and has a wafer for the wafers to enter and exit Opening, the image capturing device is set in the setting device in a manner of shooting with a fixed shooting direction toward the opening of the wafer cassette; thereby, the wafer placement state detection system can detect the inside of the wafer cassette Whether there is a wrong placement state such as wafer protruding, skewed, slanted, stacked or missing, and the cost of equipment is low.

Description

Wafer placement status detection system

This creation is related to the material status detection system, in particular to a wafer placement status detection system.

Generally speaking, the wafers are stored in a cassette after the manufacturing is completed, and a pick-and-place device takes the wafers out of the cassette, and then performs subsequent processes such as cutting and inspection. There are a plurality of placement layers in the wafer cassette, and the placement layers are respectively used to carry a wafer.

However, after the automated equipment places the manufactured wafers in the wafer cassette, some of the wafers may be placed in the wrong state, such as protruding (wafers are not completely placed on the placement layer and some are protruding. Wafer tray), skewed (when the wafer is not centered on the placement layer and there is a left or right side), oblique placement (the wafer is inclined because its left and right sides depend on different placement layers) State) or lamination (multiple wafers are placed on the same placement layer), or there may be some placement layers in the wafer cassette without wafers (lack of wafers).

The aforementioned incorrect wafer placement status will cause errors in the subsequent steps of taking out the wafer by the pick-and-place device, for example, the wafer is not picked, the wafer is eccentric or skewed on the pick-and-place arm, etc., and may even cause the wafer Dropped and damaged. Therefore, when the wafers in the entire wafer cassette have not been taken out, the detection of the placement status of the wafers in the wafer cassette will be performed first. The person will cancel the error status. The conventional methods for detecting the placement status of wafers in the wafer cassette are detected by methods such as infrared, proximity sensors, and complex optical image recognition systems. Some of the foregoing methods have higher installation costs and The volume is relatively large, which is not conducive to the space configuration of the overall equipment, so it needs to be improved.

In view of the above deficiencies, the main purpose of this creation is to provide a wafer placement state detection system that can detect whether there are errors such as wafer protrusion, skew, skew, stacking or missing wafers in the wafer cassette It is placed in a state where the equipment cost is low and the volume is small.

To achieve the above purpose, the wafer placement state detection system provided by this creation includes at least one wafer cassette, a setting device, and an image capturing device. The wafer cassette is used to store a plurality of wafers and has a For the openings for the wafers to enter and exit, the image capturing device is set in the setting device in a manner of shooting towards the opening of the wafer cassette in a fixed shooting direction.

In an embodiment of the present invention, the shooting direction is not perpendicular to the opening of the wafer cassette, in other words, the lens of the image capturing device is not directly facing the opening of the wafer cassette being photographed, but tilted toward the crystal Shooting of the opening of the round box, in which the image capturing device is directed at the center of the opening of the wafer box in such a manner that the image capturing device is inclined at an angle less than or equal to 75 degrees from top to bottom or bottom to top with respect to the wafer box Shooting is better. Alternatively, the shooting direction may be perpendicular to the opening of the wafer cassette.

When the wafer placement state detection system of this creation is used, as long as the image capture device is set in a proper position, its field of view (FOV) can cover not only the opening of the wafer cassette but also the At least one of the top surface of the wafer cassette (when shooting from top to bottom), the bottom surface (when shooting from bottom to top), the left side and the right side are close to the opening, so as long as the actual detection The photos taken are compared with the previously taken normal samples (golden sample), you can know whether there are wafer protrusions, skew, oblique, stacked or missing wafers in the wafer cassette under test problem. In addition, most of the wafer cassettes are arranged in a side-by-side and overlapping manner, and the opening directions of the wafer cassettes are consistent. Therefore, as long as the image capturing device is installed on a setting device that can generate linear displacement, Driven by the setting device, it moves to an appropriate position corresponding to each wafer cassette, and then respectively photographs the openings of the wafer cassettes in the same shooting direction, so as to perform the aforementioned detection on the wafer cassettes. In this way, the detection operation of one or more wafer cassettes can be achieved by only one image capturing device, so the cost of the detection equipment and the space-saving effect can be achieved.

The detailed structure, characteristics, assembly or use of the wafer placement status detection system provided by this creation will be described in the detailed description of the subsequent embodiments. However, those with ordinary knowledge in this creative field should be able to understand that these detailed descriptions and the specific examples listed for implementing this creative are only used to illustrate this creative, not to limit the scope of patent applications for this creative.

The applicant first explains here that in the embodiments and drawings to be described below, the same reference numbers indicate the same or similar elements or their structural features.

Please refer to FIG. 1 to FIG. 3 first, the wafer placement state detection system 10 provided in this first preferred embodiment includes four wafer cassettes 20 (the actual number is not limited to this), and a setting device 30 , And an image capture device 40 (such as a camera, a camera, etc.). In fact, the wafer cassettes 20 and the setting device 30 are set on a base and are jointly covered by a casing, but the base and the casing are not related to the technical features of this embodiment. Shown in the diagram of this embodiment.

Please refer to FIG. 1 to FIG. 5, each wafer cassette 20 includes a housing 21. The housing 21 is composed of a top plate 211, a bottom plate 212 and two side plates 213 and 214. The inside of the two side plates 213 and 214 are respectively provided There are a plurality of convex ribs 215, the convex ribs 215 are opposed to each other, thereby each wafer cassette 20 has a plurality of placement layers 22 formed by the convex ribs 215 (as shown in FIG. 4), the The isoposition layers 22 are used to store a wafer 50 respectively, as shown in FIG. 6. For example, the side plates 213 and 214 of each wafer cassette 20 in this embodiment are respectively provided with six ribs 215, so that each wafer cassette 20 has six placement layers 22 for storing six wafers 50, but it can be understood The aforementioned quantity is only an example, and the actual quantity is not limited to this. The housing 21 of each wafer cassette 20 has an opening 216 for the wafers 50 to enter and exit. The opening 216 faces the setting device 30.

In this embodiment, the setting device 30 is used to carry a pick-and-place arm (such as the pick-and-place arms 35 and 36 shown in FIGS. 12 and 13) and drive the pick-and-place arm along the X-axis, Y-axis, and Z The displacement device for the axis movement. Furthermore, the setting device 30 includes a first horizontal displacement unit 31 at the bottom, a vertical displacement unit 32 extending vertically upward from the first horizontal displacement unit 31, and a The vertical displacement unit 32 extends horizontally in the direction of the wafer magazines 20. The second horizontal displacement unit 33, the first horizontal displacement unit 31, the second horizontal displacement unit 33 and the vertical displacement unit 32 are used to generate Y The linear displacement of the axis, X-axis and Z-axis has the same structure as the conventional linear displacement mechanism, so the applicant will not elaborate here. The setting device 30 is used to drive the pick-and-place arm to take out the wafer 50 from the wafer cassette 20 and move it to other workstations to perform subsequent processes such as cutting and inspection.

As shown in FIG. 3A, the image capturing device 40 is disposed at the end of the second horizontal displacement unit 33 of the setting device 30 in a fixed shooting direction D toward the opening 216 of each wafer cassette 20, and the The shooting direction D is not perpendicular to the opening 216 of each wafer cassette 20. That is to say, the image capturing device 40 is fixed to the end of the second horizontal displacement unit 33 of the setting device 30 with the angle of its lens toward the shooting direction D, so the image capturing device 40 can be driven by the setting device 30 Moving between a plurality of shooting positions, the shooting positions refer to positions where the image capturing device 40 shoots toward the opening 216 of the wafer cassette 20 respectively, and the image capturing device 40 is between the shooting positions Only move without changing its shooting direction D. However, the image capturing device 40 is not limited to be disposed at the end of the second horizontal displacement unit 33 of the setting device 30, for example, it can also be disposed at a position as shown in FIG. 3B above the pick-and-place arm, which is at a distance from the wafer The box 20 is farther, and is suitable for the image capturing device 40 with a longer working distance. In addition, the setting device 30 is not limited to the crystal taking device as described above, but can also be a general linear displacement device, that is, the setting device 30 and the crystal taking device can be two independent displacement devices, and the displacement of the two The actions will not interfere with each other, that is to say, after the crystal pick-up device drives the pick-and-place arm to transfer the wafer 50, the distance between the image capturing device 40 and the wafer cassette 20 will not be changed, so that the image capturing device can be avoided 40 The captured image is blurry and unrecognizable. Alternatively, in the case where only one wafer cassette 20 needs to be detected, the setting device 30 may not have a displacement function, and is only provided for the image capturing device 40 to be fixedly set.

Please refer to FIG. 11 to FIG. 13, the aforementioned setting device 30 may (but is not limited to) include a rotating base 34. The rotating base 34 is relative to the first horizontal displacement unit 31 and the first horizontal displacement unit 31 through a rotating driving unit 39. The vertical displacement unit 32 is indirectly disposed on the vertical displacement unit 32 around the Z axis, and the second horizontal displacement unit 33 is disposed on the rotating base 34. More specifically, the second horizontal displacement unit 33 includes There is at least one slide rail 332 provided on the rotating base 34 for driving at least one pick-and-place arm 35, 36 into and out of the wafer cassette 20, that is, the second horizontal displacement unit 33 and the pick-up provided thereon Both the releasing arms 35 and 36 will rotate with the rotating base 34. In this aspect, the image capturing device 40 can be fixedly disposed on the rotating base 34. For example, in FIGS. 11 to 13, the setting device 30 includes a vertical extension from the rotating base 34 The support frame 37, the image capturing device 40 is set on the support frame 37, the support frame 37 and the image capturing device 40 are not set on the slide rail 332 of the second horizontal displacement unit 33, so it will not be affected The second horizontal displacement unit 33 drives, that is, when the second horizontal displacement unit 33 drives the pick-and-place arms 35 and 36 to transfer the wafer 50, for example, the state shown in FIG. 12 may be that the pick-and-place arm 36 extends to In the wafer cassette 20, the state shown in FIG. 13 may be that the pick-and-place arm 36 is retracted to take out the wafer 50 from the wafer cassette 20. During this process, the action of the second horizontal displacement unit 33 does not change the image capture The distance between the fetching device 40 and the wafer cassette 20 can prevent the image captured by the image capturing device 40 from being blurred and unrecognizable.

4 and 5 show the relative position and relative angle relationship between the image capturing device 40 and the wafer cassette 20 when the image capturing device 40 is located at each of the shooting positions. As shown in FIGS. 4 and 5, the wafer placement state detection system 10 can define a horizontal imaginary plane P1 (that is, the XY plane) that is substantially perpendicular to the opening 216 of the wafer cassette 20. In this embodiment The plane P1 is (but is not limited to) the center C2 of the opening 261 and a vertical imaginary plane P2 (ie, XZ plane) that is substantially perpendicular to the opening 216 of the wafer cassette 20. The plane P2 is (In fact, it is not limited to) through the center C2 of the opening 261, there is an acute angle θ1 (the elevation angle in this embodiment) between the shooting direction D of the image capturing device 40 of this embodiment and the horizontal virtual plane P1 , But can also be a depression angle), and the shooting direction D is substantially parallel to the vertical imaginary plane P2, that is, the image capturing device 40 is directed upward at the center of the opening 216 of the wafer cassette 20 The included angle θ1 is tilted. Therefore, the image capturing device 40 is tilted from top to bottom with respect to the wafer cassette 20 (if the included angle θ1 is a depressed angle, it is tilted from bottom to top). 20的Opening 216.

In addition, the image capturing device 40 has a front face 41 facing its shooting direction D, the front face 41 can define a first center point C1, and the opening 216 of the wafer cassette 20 can define a second center point C2, The relative position of the image capturing device 40 and the wafer cassette 20 it photographs is set in such a manner that the direction of the first center point C1 toward the second center point C2 substantially conforms to the shooting direction D.

When the wafer placement state detection system 10 of the present invention is used, as long as the image capturing device 40 is set in an appropriate position, its field of view can not only cover the opening 216 of the wafer cassette 20 it detects, but also cover At least one of the top surface 23, the bottom surface 24, the left side surface 25, and the right side surface 26 of the wafer cassette 20 is close to the opening 216, for example, in the case of top-down shooting provided in this embodiment, the image The field of view of the capturing device 40 covers the opening 216 of the wafer cassette 20 and the parts of the top surface 23, the left side surface 25 and the right side surface 26 close to the opening 216, so that the effects of front view, top view and side view can be produced at the same time. In this way, as long as the normal state of the wafer cassette 20 filled with wafers 50 is captured in advance (as shown in FIG. 6), during actual detection, the captured photo is compared with the normal state photo (golden sample) for image overlap comparison When the result of the comparison is that the difference between the two is greater than a set value (for example, 5%), it is determined that there is an abnormal placement state. In this way, it can be detected whether there is a wafer protrusion or distortion in the wafer cassette 20 under test Problems such as placement, oblique placement (as shown in Figure 7), lamination (as shown in Figure 8) or missing pieces (as shown in Figure 9).

The appropriate position of the aforementioned image capturing device 40 when shooting is based on the vertical distance d1 between the first center point C1 and the opening 216 of the wafer cassette 20 with the included angle θ1 being greater than or equal to 0 degrees and less than or equal to 75 degrees It is greater than or equal to 65 mm and less than or equal to 570 mm, and the vertical distance d2 between the first center point C1 and the top surface 23 of the wafer cassette 20 is greater than or equal to 0 mm and less than or equal to 750 mm, which is a better design. In addition, the shooting direction D of the image capturing device may not be parallel to the vertical imaginary plane P2, but the image capturing device 40' shown in FIG. 5 may be tilted laterally (leftward or rightward). The angle θ2, that is, there is an acute angle θ2 between the shooting direction D and the vertical imaginary plane P2, and the included angle θ2 is preferably designed to be greater than or equal to 0 degrees and less than or equal to 75 degrees.

In other words, there must be an angle θ1 between the shooting direction D and the horizontal imaginary plane P1 in this embodiment, and there may be no angle θ2 or an angle θ2 between the shooting direction D and the vertical imaginary plane P1, that is, It is mainly tilted upward or downward, and lateral tilt can be used as appropriate. However, the shooting direction D of the image capturing device 40 in the wafer placement state detection system of the present creation may also be tilted laterally, and may be tilted upward or downward as the case may be. In fact, the shooting direction D of the image capturing device 40 in the wafer placement state detection system of this creation can also be perpendicular to the opening of the captured wafer cassette, as long as the image capturing device 40 is relative to the captured crystal Appropriate horizontal and vertical positions of the round box can also produce the aforementioned effects.

In summary, with the created wafer placement status detection system, the detection operation of one or more wafer cassettes can be achieved with only one image capturing device, so the cost of detecting equipment can be saved .

However, as shown in FIG. 10, a second preferred embodiment of the present creation, the wafer placement state detection system of the present creation can also detect a plurality of wafer cassettes 20 by a plurality of image capturing devices 40', in other words, Regardless of whether the number of wafer cassettes 20 to be detected is singular or plural, it can be detected by a fixed image capturing device, that is, the setting device may not have a displacement function, for example, the image capturing device 40' in FIG. 10 It is fixed to a casing 38, that is, the installation device of this embodiment is the casing 38.

Finally, it must be explained again that the constituent elements disclosed in the previous disclosed embodiments are only examples and are not intended to limit the scope of the case. The substitution or change of other equivalent elements should also be the scope of the patent application of the case Covered.

10‧‧‧wafer placement status detection system 20‧‧‧wafer cassette 21‧‧‧Housing 211‧‧‧Top plate 212‧‧‧Bottom plate 213、214‧‧‧Side board 215‧‧‧rib 216‧‧‧ opening 22‧‧‧ Placement layer 23‧‧‧Top 24‧‧‧Bottom 25‧‧‧Left side 26‧‧‧right side 30‧‧‧Set device 31‧‧‧The first horizontal displacement unit 32‧‧‧Vertical displacement unit 33‧‧‧Second horizontal displacement unit 332‧‧‧slide 34‧‧‧rotating base 35, 36‧‧‧ pick and place arm 37‧‧‧Support frame 38‧‧‧Chassis 39‧‧‧Rotary drive unit 40、40’‧‧‧Image capture device 41‧‧‧Front 50‧‧‧ Wafer C1‧‧‧First center point C2‧‧‧Second Center Point D‧‧‧ Shooting direction d1, d2‧‧‧ vertical distance P1‧‧‧horizontal imaginary plane P2‧‧‧Vertical imaginary plane θ1, θ2 ‧‧‧ included angle

1 and 2 are three-dimensional assembly diagrams of a wafer placement state detection system provided by a first preferred embodiment. FIG. 3A is a front view of FIG. 2. FIG. 3B is similar to FIG. 3A, except that the image capturing device of one of the wafer placement state detection systems has a different installation position. 4 is a schematic cross-sectional view of one wafer cassette and the image capturing device of the wafer placement state detection system. FIG. 5 is a schematic top view of the wafer cassette and the image capturing device. FIG. 6 is a schematic side view of the wafer cassette and the image capturing device, but it also shows a plurality of wafers placed in the wafer cassette in a normal state. FIG. 7 is similar to FIG. 6, except that a wafer in the wafer cassette is in a skewed state. FIG. 8 is similar to FIG. 6 except that one of the wafer cassettes is stacked. Fig. 9 is similar to Fig. 6, but shows that one of the wafer cassette placement layers is in a missing state. 10 is a schematic top view of a wafer placement state detection system provided by a second preferred embodiment. FIG. 11 is similar to FIG. 3B, except that the position of the image capturing device of one of the wafer placement state detection systems is different. 12 and 13 are partial perspective views of the wafer placement state detection system shown in FIG. 11, respectively showing a state where a pick-and-place arm is extended and retracted.

10‧‧‧wafer placement status detection system

20‧‧‧wafer cassette

216‧‧‧ opening

30‧‧‧Set device

31‧‧‧The first horizontal displacement unit

32‧‧‧Vertical displacement unit

33‧‧‧Second horizontal displacement unit

40‧‧‧Image capture device

Claims (25)

A wafer placement status detection system, including: At least one wafer cassette, the wafer cassette is used to store a plurality of wafers, and has an opening for the wafers to enter and exit; A setting device; and An image capturing device is arranged on the setting device in a manner that a fixed shooting direction shoots toward the opening of the wafer cassette. The wafer placement state detection system as described in item 1 of the patent application scope, wherein the wafer placement state detection system can define a horizontal imaginary plane substantially perpendicular to the opening of the wafer cassette, the image is captured There is an angle between the shooting direction of the device and the horizontal imaginary plane. The wafer placement state detection system as described in item 2 of the patent application scope, wherein the angle between the shooting direction of the image capture device and the horizontal imaginary plane is greater than or equal to 0 degrees and less than or equal to 75 degrees. The wafer placement status detection system as described in item 2 of the patent application scope, wherein the wafer placement status detection system can define a vertical imaginary plane substantially perpendicular to the opening of the wafer cassette, the image is captured The shooting direction of the device is substantially parallel to the vertical imaginary plane. The wafer placement state detection system as described in item 4 of the patent application scope, wherein the angle between the shooting direction of the image capture device and the horizontal imaginary plane is greater than or equal to 0 degrees and less than or equal to 75 degrees. The wafer placement status detection system as described in item 2 of the patent application scope, wherein the wafer placement status detection system can define a vertical imaginary plane substantially perpendicular to the opening of the wafer cassette, the image is captured There is another angle between the shooting direction of the device and the vertical imaginary plane. The wafer placement state detection system as described in item 6 of the patent application scope, wherein the angle between the shooting direction of the image capturing device and the vertical imaginary plane is greater than or equal to 0 degrees and less than or equal to 75 degrees. The wafer placement state detection system as described in item 7 of the patent application scope, wherein the angle between the shooting direction of the image capture device and the horizontal imaginary plane is greater than or equal to 0 degrees and less than or equal to 75 degrees. The wafer placement state detection system as described in any one of items 1 to 8 of the patent application scope, wherein the image capturing device is inclined to photograph the wafer from top to bottom or from bottom to top with respect to the wafer cassette Opening of wafer cassette. The wafer placement state detection system as described in item 9 of the patent application scope, wherein the image capture device has a front face facing its shooting direction, and the front face can define a first center point, the wafer cassette The opening can define a second center point. The relative position of the image capturing device and the wafer cassette it photographs is set in such a way that the direction of the first center point toward the second center point substantially conforms to the shooting direction. The wafer placement state detection system as described in item 10 of the patent application scope, wherein the wafer placement state detection system includes a plurality of the wafer cassettes, and the image capturing device can be driven by the setting device to the plural Moving between the shooting positions, when the image capturing device is located at the shooting positions, it shoots toward the openings of the wafer cassettes in the shooting direction respectively. The wafer placement state detection system as described in item 11 of the patent application scope, wherein the vertical distance between the first center point and the opening of the wafer cassette is greater than or equal to 65 mm and less than or equal to 570 mm. The wafer placement status detection system as described in item 12 of the patent application scope, wherein the vertical distance between the first center point and a top surface or a bottom surface of the wafer cassette is greater than or equal to 0 mm and less than or equal to 750 Mm. The wafer placement state detection system as described in item 1 of the patent application scope, wherein the wafer placement state detection system can define a vertical imaginary plane substantially perpendicular to the opening of the wafer cassette, the image is captured There is an angle between the shooting direction of the device and the vertical imaginary plane. The wafer placement state detection system as described in item 14 of the patent application scope, wherein the angle between the shooting direction of the image capturing device and the vertical imaginary plane is greater than or equal to 0 degrees and less than or equal to 75 degrees. The wafer placement state detection system as described in item 15 of the patent application scope, wherein the wafer placement state detection system can define a horizontal imaginary plane substantially perpendicular to the opening of the wafer cassette, the image is captured There is another angle between the shooting direction of the device and the horizontal imaginary plane. The wafer placement state detection system as described in item 16 of the patent application range, wherein the angle between the shooting direction of the image capture device and the horizontal imaginary plane is greater than or equal to 0 degrees and less than or equal to 75 degrees. The wafer placement state detection system as described in any of items 1 to 8 and 14 to 17 of the patent application scope, wherein the image capturing device has a front side facing its shooting direction, and the front side can be defined A first center point is formed, and the opening of the wafer cassette can define a second center point, and the relative position of the image capturing device and the wafer cassette photographed is directed from the first center point to the second center point The direction of the camera is substantially in accordance with the shooting direction. The wafer placement status detection system as described in any one of patent application items 1 to 8 and items 14 to 17, wherein the wafer placement status detection system includes a plurality of the wafer cassettes, and the image is captured The fetching device can be driven by the setting device to move between a plurality of shooting positions. When the image capturing device is located at the shooting positions, it shoots toward the openings of the wafer cassettes in the shooting direction. The wafer placement state detection system as described in item 19 of the patent application scope, wherein the image capture device has a front side facing its shooting direction, and the front side can define a first center point, the wafer cassette The opening can define a second center point. The relative position of the image capturing device and the wafer cassette it photographs is set in such a way that the direction of the first center point toward the second center point substantially conforms to the shooting direction. The wafer placement state detection system as described in any of items 1 to 8 and 14 to 17 of the patent application scope, wherein the image capturing device has a front side facing its shooting direction, and the front side can be defined A center point is formed, and the vertical distance between the center point and the opening of the wafer cassette is greater than or equal to 65 mm and less than or equal to 570 mm. The wafer placement status detection system as described in any one of patent application items 1 to 8 and items 14 to 17, wherein the setting device includes a horizontal displacement for driving a pick and place arm into and out of the wafer cassette Unit, the image capturing device is installed on the setting device without being driven by the horizontal displacement unit. The wafer placement state detection system as described in item 22 of the patent application scope, wherein the setting device includes a rotating base, the horizontal displacement unit is mounted on the rotating base, and the image capturing device is fixedly set On the rotating base. The wafer placement state detection system as described in any one of patent application items 1 to 8 and items 14 to 17, wherein the setting device includes a rotating base, and the image capturing device is fixedly installed in The rotating base. The wafer placement state detection system as described in item 24 of the patent application scope, wherein the setting device includes a horizontal displacement unit provided on the rotating base, and the image capturing device is not driven by the horizontal displacement unit Set on the rotating base.

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