JP2004045200A - Inspection device and inspection method for inspecting appearance of inspection object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inspect an appearance of an inspection object, for example, a semiconductor chip, a substrate with a pattern or a film with a pattern, to classify a defective from a non-defective. <P>SOLUTION: In this device/method, an image picking-up means A for measuring an angle and a position of the inspection object, and an image picking-up means B having at least an angle control means and for inspecting the appearance are provided with a prescribed space along a conveyer for mounting the inspected object to be conveyed unidirectionally in order, and the image picking-up means B is controlled, based on positional information of the inspected object acquired by the image picking-up means A. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a visual inspection apparatus and a visual inspection method for performing a visual inspection of a product to be inspected, for example, a semiconductor chip, a substrate with a pattern, or a film with a pattern, and separating the inspected product into non-defective products and defective products.
[0002]
[Prior art]
In a semiconductor chip manufacturing process, a semiconductor wafer on which a pattern is formed is diced and divided into individual semiconductor chips. However, in the dicing process, the semiconductor chip may be cracked or chipped, or the chip surface may be stained or damaged.
[0003]
Such defective semiconductor chips need to be separated from non-defective semiconductor chips and eliminated, and a visual inspection apparatus as shown in FIG. 6 has been used conventionally. That is, the semiconductor chip 2 accommodated in the tray 3d is vacuum-adsorbed from above by the collet 40, moved to the inspection stage 42 provided on the XYθ stage 41, and the semiconductor chip 2 is fixed by the vacuum suction at the inspection stage 42. After that, the position and angle of the semiconductor chip 2 are measured by the camera 43 with a microscope provided thereabove, and the inspection stage 41 is moved and rotated based on the measurement data to correct the position. And an image processing unit (not shown) performs an inspection process on the input image.
[0004]
[Problems to be solved by the invention]
Inspection using image processing is generally performed by comparing a non-defective product image of the product to be inspected stored in the image processing unit in advance with an image of the product to be inspected. In order to perform image processing inspection with high accuracy, it is necessary to compare images at the grayscale image level. In addition, the angle and position of the inspected product image with respect to the non-defective image stored in the image processing unit are less than the resolution of the imaging system It is preferable to strictly match them so that
[0005]
In the above-described conventional inspection apparatus, the semiconductor chips housed in the tray 3d for both pre-inspection and re-inspection product chips are moved one by one to the inspection position by the collet 40, which is a pickup mechanism, and the semiconductor chips are removed at that position. The angle and the position are measured, the position is corrected so as to come to a predetermined position based on the respective measured values, an inspection is performed, and based on the inspection result, the collet 40 re-uses the non-defective tray 3c or the chip tray before the inspection. It was stored in the inspection chip storage tray 3d. In this case, the movement of the inspection object, the measurement of the angle and the position, the correction of the angle and the position, the inspection, and the movement of the inspection object cannot be performed at the same time. . As another method, the angle and the position are measured, the rotation and the position processing are converted so that the captured image of the inspected product comes to a predetermined position inside the image processing apparatus, and the deviation from each of the predetermined values is performed. Although it is conceivable to correct the amount, rotating the image reduces the accuracy of the image information, reduces the amount of image information itself, and increases the number of images taken for inspection. Further, when a plurality of images are required for the inspection of the inspected product, it is necessary to perform the above-described image rotation and position movement processing on the plurality of images, which lowers the accuracy of the inspection and requires a long time. There is.
[0006]
Therefore, an object of the present invention is to provide an appearance inspection apparatus and an appearance inspection method capable of executing an appearance inspection of an object to be inspected, for example, a semiconductor chip, a patterned substrate, or a patterned film with high accuracy and in a short time. It is in.
[0007]
[Means for Solving the Problems]
The inspection device according to claim 1, wherein the inspection device is configured to measure at least an angle of the inspection object along a transport device on which the inspection object is placed and forwarded in one direction. A and an imaging unit B having at least an angle control function and performing an appearance inspection are provided at a predetermined interval, and the angle of the imaging unit B is controlled based on angle information from the imaging unit A. Things. As described above, two imaging units are arranged, and first, the angle is measured by the imaging unit A, and the appearance inspection is performed by the imaging unit B at the subsequent stage where the inspection position is controlled and adjusted in advance based on the angle information. The tact time of the inspection per inspection object can be greatly reduced without lowering the accuracy.
[0008]
According to a second aspect of the present invention, there is provided an appearance inspection apparatus for an inspected product, wherein the imaging unit A has a function of measuring an angle and a position (XY direction position). According to this structure, the inspection accuracy can be further improved as compared with the first aspect of the invention.
[0009]
According to a third aspect of the present invention, there is provided an appearance inspection apparatus for an inspected product, wherein the inspected product is placed on the transport device along a transport device on which the inspected product is placed and forwarded in one direction. An inspection object transfer mechanism to be inspected, an imaging unit A for measuring an angle and / or a position (XY direction position) of the inspection object, and an imaging unit B having an angle and / or a position (XY direction position) control function And an inspection product taking-in mechanism for obtaining an inspection product are provided at predetermined intervals. As described above, if the inspection object transfer mechanism and the inspection item take-in mechanism are provided, the appearance inspection of the inspection object can be efficiently performed.
[0010]
Further, according to a fourth aspect of the present invention, there is provided a visual inspection apparatus for an inspected product according to any one of claims 1 to 3, wherein the inspected product is a semiconductor chip or a pattern. Characterized in that it is a substrate with an attachment.
[0011]
The inspection device for inspecting an inspected product according to claim 5 further includes an imaging unit A that measures at least an angle of the inspected product along a transport path that feeds the inspected product by a tape, and at least an angle control function. The image pickup means B for performing a visual inspection is provided at a predetermined interval, and the angle of the image pickup means B is controlled based on information from the image pickup means A. This is effective when the inspected product is a wiring pattern on a film.
Further, according to a sixth aspect of the present invention, in the inspection method using the appearance inspection apparatus according to the third aspect, the angle and / or the angle of the inspection object acquired from the imaging unit A is provided. Based on the position information, the mounting angle and / or mounting position correction on the transport device by the inspected product transfer mechanism and the acquisition angle and / or position correction from the transport device by the inspection product loading mechanism are performed. It is characterized by performing each. As described above, the mounting angle and / or the mounting position of the inspected product on the transport device are corrected based on the information from the imaging unit A, and the angle obtained from the transport device by the inspected product capturing mechanism and / or By performing the position correction, the operations of transfer, placement, angle / position measurement, inspection, capture, and storage can be performed simultaneously and accurately, so that the tact time of the inspected product can be drastically reduced. Furthermore, by controlling the placement and / or take-in position, the inspected inspected product is accurately stored in the non-defective chip tray, the re-tested chip tray, or the like, and the occurrence of storage trouble is suppressed.
[0012]
Furthermore, the invention according to claim 7 is a product produced using the appearance inspection device according to any one of claims 1 to 4.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention in which a semiconductor chip is an inspection object will be described with reference to FIGS.
[0014]
Reference numeral 1 denotes an inspection object supply mechanism for supplying a tray 3a containing a plurality of semiconductor chips 2 to a predetermined position. Reference numeral 4 denotes an inspection object transfer mechanism for transferring the semiconductor chips 2 stored in the tray 3a one by one to the mounting position of the transfer device 5. The inspection object supply mechanism 1 and the inspection object transfer mechanism 4 are arranged upstream of the transport device 5. The transfer device 5 is movable in one direction at a constant pitch while the semiconductor chip 2 is being sucked, and a correction station 6 and an inspection station 7 are arranged at a predetermined interval downstream of the transfer path. The correction station 6 has a camera 8 with a microscope as an imaging means A for measuring the angle and position of the semiconductor chip 2, and the inspection station 7 has at least an angle control function (hereinafter referred to as a θ function). Cameras 9 with microscopes, which are imaging means B, are provided on the XYZ stages on the angle stage, respectively. Note that the θ function means a function that is rotatable and controllable about a vertical axis with respect to the transfer surface of the transfer device 5. Further, the imaging means B has a function (hereinafter, referred to as an XY function) that can be moved and controlled in two directions perpendicular to a plane parallel to the transport surface. This is necessary when the size of the region to be inspected does not fit within one field of view of the camera 8 with a microscope with a predetermined margin, and providing the camera 9 with a microscope at the center position of the XY function reduces the mechanical configuration. Is preferred. Furthermore, the inspection object may be provided with a function (hereinafter, referred to as a Z function) that can be moved and controlled in the direction of a vertical axis with respect to the transport surface, and a camera 9 with a microscope is provided at a center position of the Z function. This is preferable in that the thickness of the semiconductor chip 2 changes depending on the type of the semiconductor chip 2 and the change in the distance from the camera 9 with a microscope due to the transfer position of the transfer device 5 and the camera is focused.
When the camera 9 with a microscope is provided with a θ function and an XYZ function (XYZ stage), it is better to arrange the XYZ function on the θ function (angle stage), after adjusting the angle, from position control in the XY direction to the angle. This is preferable because the control can be simplified because the influence of the above can be eliminated.
Similarly, it is necessary that the imaging means A also have an XYZ function, and it is preferable that the camera 8 with a microscope is arranged at the center of the XYZ function of the imaging means A.
Reference numeral 10 denotes an inspection product taking-in mechanism, which transfers an inspection product inspected by the camera 9 with a microscope to the inspection product storage mechanism 11. In this embodiment, the inspection product storage mechanism is divided into two groups, that is, a non-defective product chip tray storage mechanism 11a and a re-test product chip tray storage mechanism 11b in order to separate and store the non-defective product and the retest product including the defective product based on the inspection result. Is provided. When the inspection result is three, that is, a non-defective product, a product requiring re-inspection, and a defective product, a corresponding inspection product storage mechanism may be separately provided.
[0015]
Next, a method of inspecting a semiconductor chip using the inspection device for inspecting an object to be inspected will be described.
[0016]
The semiconductor chip 2 to be inspected is transferred from the tray 3a to the upstream mounting position 2a of the movable transfer device 5 by the inspection object transfer mechanism 4. The semiconductor chip 2 transferred to the transfer device 5 is fixed by suction on the transfer device 5 and is moved in units of a constant pitch p. A camera 8 with a microscope of the image pickup means A is provided at a correction station 6 installed above a position where the transfer device 5 has moved i times the constant pitch p (i is an integer). The semiconductor chip 2 is conveyed immediately below and when stopped, the angle and position of the semiconductor chip 2 are measured. Immediately below the imaging means A, when the size of the semiconductor chip 2 to be inspected fits within one field of view of the camera 8 with a microscope with a predetermined margin, the center of the semiconductor chip 2 is It is preferable that the position be a "haze" position which is the center of the field of view of the camera 8.
Each time the transport device 5 moves by the constant pitch p, the inspection object transfer mechanism 4 supplies the semiconductor chip 2 to be inspected next to the upstream mounting position of the transport device 5.
Then, for all the semiconductor chips 2 on the transfer device 5 that have passed through the correction station 6, the angle and position information measured by the camera 8 with a microscope are individually stored in the memory in the device. After the angle and the position of the semiconductor chip 2 are measured, the transport device 5 moves to the downstream side by j times (j is an integer) of the constant pitch p. An inspection station 7 provided with a camera 9 with a microscope, which is an imaging means B for performing an appearance inspection, is installed above the portion moved by the j × p pitch. In the inspection station 7, the semiconductor chip 2 is stored. Based on the obtained angle / position information, the camera 9 with the microscope is operated at least in the θ function, preferably in the θ · XYZ function while the semiconductor chip 2 to be inspected moves from the standby position one pitch upstream to the inspection position of the inspection station 7. Automatically moves to the visual inspection position and waits. The camera with microscope 9 captures an image of the semiconductor chip 2 when the transfer device 5 stops, and starts inspection. When the inspection area of the semiconductor chip 2 exceeds the visual field area of the camera 9 with a microscope, the semiconductor chip 2 is divided into a plurality of inspection visual fields by using the camera 9 with a microscope having at least the XY function. Of course you can.
Next, the first semiconductor chip 2 for which the appearance inspection has been completed is further transported downstream by k times (k is an integer) of the constant pitch p, and stops at the take-in position 2b. It is moved to the storage mechanism 11.
[0017]
That is, when the appearance inspection of the M-th semiconductor chip 2 is performed by the camera 9 with a microscope, the angle and position of the (M + j) -th semiconductor chip are measured by the camera 8 with a microscope arranged in the correction station 6. The (M−k) th semiconductor chip is moved to the inspection product storage mechanism 11 by the inspection product take-in mechanism 10, and the (M + i + j) th semiconductor chip is moved to the mounting position by the inspection product transfer mechanism 4. Will be transferred.
[0018]
The angle and the position information measured by the camera 8 with the microscope of the correction station 6 during the moving time when the semiconductor chip moves to the mounting position 2a, the correction station 6, the inspection station 7, and the take-in position 2b are respectively , And each time, the mounting angle and / or mounting position 2a of the inspection object transfer mechanism 4 on the upstream side of the transport device 5 and the inspection angle and / or Alternatively, the inspection position, the angle of the inspection product taking-in mechanism 10 from the downstream side of the transport device 5 and / or the take-in position 2b are corrected.
In this way, the transfer device 5 continuously moves the semiconductor chip 2 in the unit of the constant pitch p to the downstream side, so that the transfer, placement, angle and position measurement, inspection, and removal of the semiconductor chip are performed at the same timing. In addition, it becomes possible to carry out the inspection continuously and efficiently in a sequential manner.
[0019]
Until now, the case where the inspected product is a semiconductor chip has been described, but it is needless to say that the same can be applied to the case of a patterned substrate.
3 and 4 are a plan view and a side view, respectively, showing another embodiment of the device for inspecting the appearance of a product to be inspected according to the present invention, wherein the product to be inspected is a wiring pattern on a film.
In this case, the inspected product supply mechanism 1 corresponds to the sending device 20, and the inspected product take-in mechanism 10 corresponds to the winding machine 23. In this case, the tape feed amount constant pitch p is a repetition pitch in the winding direction of the unit pattern on the film, and the distance in the tape feed direction between the correction station 6 and the inspection station 7 is j times (j) the tape feed amount constant pitch p. Is an integer.) And the distance between the inspection station 7 and the NG puncher 22 in the tape feed direction is k times the tape feed amount constant pitch p (k is an integer). Defective products are punched out by the NG puncher 20. Other mechanisms are the same as those of the embodiment shown in FIGS.
[0020]
FIG. 5 is a plan view showing another embodiment of the appearance inspection apparatus for an object to be inspected according to the present invention, in which the transport device 5 of FIGS. In this embodiment, a coarse positioning mechanism 30 is provided on the upstream side of the correction station 6, but the other mechanisms are the same as those of the embodiment shown in FIGS.
[0021]
【The invention's effect】
In the past, operations such as transfer, placement, measurement of angle and position, inspection, capture, and storage were performed in a series at the same location, requiring a long time for inspection. According to the apparatus and the appearance inspection method, the operations of transfer, placement, angle / position measurement, inspection, take-in, and storage can be performed at the same time. It is possible to shorten the time and perform high-precision visual inspection. Further, when the inspected product is a semiconductor chip or a substrate with a pattern, the placement and / or taking-in position is controlled to store the inspected inspected product in a non-defective chip tray, a re-inspected chip tray, or the like. Is carried out accurately, and occurrence of storage trouble is suppressed.
[Brief description of the drawings]
FIG. 1 is a plan view showing an outline of an appearance inspection apparatus for an object to be inspected according to the present invention.
FIG. 2 is a side view of the appearance inspection apparatus of the inspection object of the present invention shown in FIG.
FIG. 3 is a plan view showing another embodiment of the appearance inspection device for an inspected product of the present invention.
FIG. 4 is a side view showing another embodiment shown in FIG. 3;
FIG. 5 is a plan view showing another embodiment of the appearance inspection apparatus for an inspected product of the present invention.
FIG. 6 is a conceptual diagram showing an example of a conventional semiconductor chip appearance inspection apparatus.
[Explanation of symbols]
1 inspection product supply mechanism 2 semiconductor chip 2a mounting position 2b take-in position 3 chip tray 3a pre-inspection chip tray 3b re-inspection product chip tray 3c non-defective product chip tray 3d pre-inspection / re-inspection product chip combined tray 4 chip tray supply mechanism 5 Conveying device 6 Correction station 7 Inspection station 8 Camera with microscope 9 Camera with microscope 10 Inspection product take-in mechanism 11 Chip tray storage mechanism 11a Good chip tray storage mechanism 11b Re-test product chip tray storage mechanism 20 Sending device 21 Print film 22 NG Puncher 23 Winder 30 Rough positioning mechanism 31 Rotary table 40 Collet 41 XYθ stage 42 Inspection stage 43 Camera with microscope

Claims (7)

Along the transport device that places the product to be inspected and is fed in one direction,
An imaging unit A for measuring at least the angle of the inspection object and an imaging unit B having at least an angle control function and performing an appearance inspection are provided at a predetermined interval, and an imaging unit based on information from the imaging unit A A visual inspection apparatus for an inspected product, wherein the angle of B is controlled. 2. The visual inspection apparatus according to claim 1, wherein the imaging unit A has a function of measuring an angle and a position (an XY direction position). An inspected article transfer mechanism for mounting the inspected article on the transport apparatus along a transport apparatus on which the inspected article is placed and sequentially fed in one direction; and an angle and / or position of the inspected article ( The imaging unit A for measuring the position in the XY direction), the imaging unit B having an angle and / or position (XY position) control function, and the inspection product taking-in mechanism for obtaining the inspection product are spaced apart from each other by a predetermined distance. Apparatus for inspecting the appearance of a product to be inspected, which is provided. 4. The visual inspection device for an inspected product according to claim 1, wherein the inspected product is a semiconductor chip or a substrate with a pattern. Along the conveyance path for feeding the product to be inspected, an imaging unit A for measuring at least the angle of the product to be inspected and an imaging unit B having at least an angle control function and performing an appearance inspection are spaced apart by a predetermined distance. A visual inspection apparatus for inspecting an inspection object, wherein the angle of the imaging means B is controlled based on information from the imaging means A. The inspection method using the appearance inspection device according to claim 3, wherein the inspection object transfer mechanism mounts the inspection object on the transport device based on the angle and / or position information of the inspection object obtained from the imaging unit A. 5. A method for inspecting the appearance of a product to be inspected, wherein correction of an angle and / or a mounting position and correction of an angle and / or a position obtained from the transport device by an inspection product take-in mechanism are performed. A product produced using the visual inspection device according to claim 1.

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