JP3028789B2 - Recognition resolution measuring method and bonding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recognition resolution measuring method, and more particularly, to a recognition resolution measuring method for a bonding apparatus using image processing for position recognition and measurement.

[0002]

2. Description of the Related Art Conventionally, this kind of recognition resolution measuring method has
For example, it is used for aligning a semiconductor pellet and a substrate on which the semiconductor pellet is mounted with high accuracy. In this alignment, the resolution of the image processing apparatus (the distance of one pixel constituting the acquired image) is taught. Then, the position of the semiconductor pellet is calculated from the image processing result.

As an example used for implementing a conventional recognition resolution measuring method, there is a bonding apparatus having a teaching function of resolution in an image processing apparatus itself. Using a dedicated interface of the image processing apparatus itself, for example, a console, the target mark registered in the image processing apparatus is sequentially moved to a designated position designated by the image processing apparatus. The movement of the target mark is performed by the operator instructing the stage movement using the operation panel of the bonding apparatus.

[0004] Another example is a bonding apparatus in which the image processing apparatus does not have a function of teaching the resolution. The bonding device includes a recognition device that recognizes a recognition target mark,
An image processing device for registering and retrieving a target mark, an XY stage unit that moves to make the recognition device recognize the target mark, a stage drive unit that drives and controls the XY stage unit, and image processing that controls the image processing device The control unit includes a control unit, a stage control unit that controls the stage driving unit, a recognition position obtaining unit that obtains image processing result data, and a stage position obtaining unit that obtains position data of the XY stage unit. The order of teaching in this example will be described. First, the operator moves the XY stage to a position where the target mark can be recognized by the recognition device, and causes the image processing device to execute image processing. The recognition position and the stage position at this time are obtained by the recognition position obtaining means and the stage position obtaining means. Next, the operator moves the XY stage to another position where the target mark can be recognized by the recognition device, and causes the image processing device to execute image processing. As in the previous case, the recognition position and the stage position at this time are obtained by the recognition position obtaining means and the stage position obtaining means. After that, the resolution of the image processing apparatus was calculated based on the obtained two recognition positions and the stage position.

[0005]

However, the above-described prior art recognition resolution measuring method has the following problems.

A first problem is that an erroneous operation by an operator occurs. The reason is that it is necessary to move the target mark to the designated position. Also, because the operator operates the stage, the stage may be moved out of the recognition range.

[0007] The second problem is that the positioning accuracy of the stage changes depending on the operation during teaching.
The reason is that the operator moves the stage to the designated position, which affects the accuracy of movement to the designated position.

An object of the present invention is to provide a method of measuring a recognition resolution and a bonding apparatus for eliminating an erroneous operation by an operator in view of the above-mentioned problems of the prior art.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention, a recognition target mark is moved by a moving stage, the position of the recognition target mark is recognized using a recognition device, and the recognition device is used. In the recognition resolution measuring method for measuring the recognition resolution of image processing, the recognition target mark is moved within a field of view of the recognition device by the operation of the stage.
Moving by more than a point, obtaining the position of the recognition target mark by the number of pixels by the recognition device, obtaining the position of the stage when obtaining the position of the recognition target mark, and performing the recognition before and after the movement. Calculating a rotational offset and a recognition resolution of the recognition device with respect to the stage from the position of the target mark and the position of the stage.

[0010] The bonding apparatus used for implementing the recognition resolution measuring method moves the recognition target mark by four or more points within the field of view of the recognition apparatus by the operation of the stage, and moves the position of the recognition target mark by the recognition apparatus. Recognition position obtaining means for obtaining the number of pixels, stage position obtaining means for obtaining the position of the stage when obtaining the position of the recognition target mark, and the position of the recognition target mark and the position of the stage before and after movement And a resolution calculating means for calculating a rotation offset of the recognition device from the stage and a recognition resolution.

Specifically, the boding device of the present invention comprises:
A recognition device for recognizing a recognition target mark, an image processing device for registering and retrieving the recognition target mark, a moving stage unit for moving the position recognition target mark for recognition by the recognition device, and driving the stage unit A stage drive unit for controlling, and at least an arithmetic processing unit for controlling the image processing device and the stage drive unit and calculating a rotational offset and a recognition resolution of the recognition device with respect to the stage from a mark recognition position and a stage position. It is a thing. In this case, more specifically, the arithmetic processing unit includes an image processing control unit that controls the image processing device, a stage control unit that controls the stage driving unit, and the mark recognition position data by the image processing. A recognition position acquisition unit that acquires the number of pixels from the image processing apparatus, a stage position acquisition unit that acquires the position data of the stage unit from the stage driving unit, and four memories that store data of a mark recognition position and a stage position. It is conceivable that the apparatus has a resolution calculation means for calculating a rotation offset and a recognition resolution of the recognition device with respect to the stage from the data in these memories.

In the method for measuring the recognition resolution of the image processing apparatus in such a bonding apparatus, there is provided a first step in which an already-targeted target mark position is written to a stage target position in a control memory of the stage control means; A second stage in which 0 is written to the number of stage movements in the control memory of the stage control means, a third stage in which the movement stage section is moved to a target stage position by the stage control means, and a movement of the movement stage section After the completion, a fourth step in which an image processing execution command is output from the image processing control means to the image processing apparatus, and after the image processing is performed, a mark recognition position and a stage are determined by the recognition position obtaining means and the stage position obtaining means. A fifth stage in which position data is acquired, and a stage in a control memory of the stage control means. A sixth step in which 1 is added to the number of movements, and when the number of movements of the stage is 1, the acquired position data is stored in the first memory in the resolution calculation means, and the designated position data is adjusted to the magnification of the recognition device. After the position is written to the stage target position in the control memory of the stage control means, the seventh stage to be executed from the third stage to the sixth stage, and the acquired position when the number of times of stage movement is two The data is stored in a second memory in the resolution calculating means, and the first data stored in the resolution calculating means is
At least an approximate resolution is calculated from the position data in the memory and the second memory, and a position of several pixels from the target mark position is calculated in both the X and Y directions using the calculated approximate resolution. An eighth stage for executing from the third stage to the sixth stage after being written to the stage target position in the memory for use, and when the number of times of stage movement is 3, the acquired position data is stored in the resolution calculating means. The position of minus several pixels from the target mark position is calculated in both the X and Y axis directions using the approximate resolution calculated in the eighth step and stored in the third memory,
When the ninth stage is executed from the third stage to the sixth stage after being written to the stage target position in the control memory of the stage control means, and when the number of times of stage movement is 4, the acquired position data is The resolution calculating means calculates at least the resolution of the image processing by the recognition device from the position data of the third memory and the fourth memory stored in the fourth memory in the resolution calculating means. And a tenth step performed sequentially.

(Operation) In the invention described above, the position recognition target mark is moved within the field of view of the recognition device, and the recognition is repeated. In other words, the recognition target mark that has already been taught is moved to a prescribed position by moving the moving stage unit in accordance with an instruction from the arithmetic processing unit and subjected to image processing, and the stage position and the mark recognition position are used to determine the stage of the recognition device. The rotation offset and the recognition resolution are calculated by the arithmetic processing unit.

More specifically, the arithmetic processing unit includes a recognition position obtaining unit that obtains a mark recognition position by the recognition device from the image processing device by the number of pixels [pixels], and a stage that obtains a stage position from the stage control unit. It includes a position obtaining unit and a resolution calculating unit. The recognition target mark is moved to the target position by the movement of the stage, and after executing the image processing, the position data in each of the recognition position acquisition unit and the stage position acquisition unit is read into the resolution calculation unit. Then, the resolution calculation means calculates a rotational offset [rad] with respect to the stage of the recognition device and a recognition resolution [m / pixel] from the read stage position and recognition position.

The term "resolution" as used in the present invention refers to a distance equivalent to one pixel when an image of a certain object is recognized using a recognition device (for example, a CCD camera).

[0016]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a characteristic portion of a bonding apparatus used for implementing a method for measuring a recognition resolution according to the present invention.

The bonding apparatus of this embodiment has a function of measuring the recognition resolution of the recognition apparatus.
As shown in (1), a recognition device (for example, a CCD camera) 1 for recognizing a mark for position recognition, an image processing device 2 for registering / retrieving the target mark, and a movement for causing the recognition device 1 to recognize the mark for position recognition. XY stage unit 5 and X
A stage driving unit 6 for driving and controlling the Y stage unit 5 and a CPU 10 as an arithmetic processing unit for controlling the image processing device 2 and the stage driving unit 6 and calculating the resolution of image processing from the mark recognition position and the stage position are provided. Have.

The CPU 10 includes an image processing control unit 4 for controlling the image processing device 2, a stage control unit 8 for controlling the stage driving unit 6, and a mark recognition position data by the image processing. It has a recognition position acquisition means 3 for acquiring in [pixels], a stage position acquisition means 7 for acquiring the position data of the stage section 5 from the stage drive section 6, and four memories for storing mark recognition position and stage position data. And resolution calculation means 9 for calculating at least the resolution [m / pixel] of image processing by the recognition device from the data in these memories.

Next, an operation procedure for measuring the recognition resolution of the recognition device in the above bonding apparatus is shown in FIG.
This will be described with reference to FIG. FIG. 2 is a flowchart showing an operation procedure for measuring the resolution in the bonding apparatus shown in FIG.

In FIG. 2, first, the target mark position which has already been taught is written to the stage target position in the control memory of the stage control means 8 (step A1). Then, “0” is written as the number of stage movements in the control memory of the stage control means 8 (step A2). Thereafter, the stage is moved to the target position by the stage control means 8 (step A3). When the movement of the stage is completed, an image processing execution command is output from the image processing control means 4 to the image processing apparatus 2 (step A).
4). After executing the image processing, the mark recognition position [pixel] is obtained by the recognition position obtaining means 3 and the stage position obtaining means 7.
And data of the stage position [m] are obtained (step A5). Thereafter, 1 is added to the number of stage movements in the control memory of the stage control means 8 (step A).
6). The next execution routine is determined based on the number of stage movements (step A7).

Since the number of times of stage movement is "1", the acquired position data is stored in the memory 1 in the resolution calculating means 9 (step A8), and the designated position (only in the X-axis direction) matching the magnification of the recognition device 1 Movement) is written to the stage target position in the control memory of the stage control means 8 (step A9). Then, steps A3 to A7 are executed. As a result, the number of stage movements is “2”
And the acquired position data is stored in the memory 2 in the resolution calculating means 9 (step A10). The approximate resolution [m / pixel] is calculated from the position data in the memories 1 and 2 stored in the resolution calculation means 9 (step A11). Using the approximate resolution [m / pixel] calculated in step A11, 128
The position of the pixel is calculated in both the X and Y axis directions, and is written to the stage target position in the control memory of the stage control means 8 (step A12).

Further, steps A3 to A7 are executed, the number of stage movements becomes "3", and the acquired position data is stored in the memory 3 in the resolution calculating means 9 (step A13). Using the approximate resolution [m / pixel] calculated in step A11, the position of -128 pixels from the target mark position is calculated in both the X and Y axis directions, and the stage target in the control memory of the stage control means 8 is calculated. It is written to the position (step A14). Steps A3 to A7 are executed again, the number of stage movements becomes "4", and the acquired position data is stored in the memory 4 in the resolution calculation means 9 (step A15).
At least the resolution [m / pixel] of the image processing by the recognition device is calculated by the resolution calculation means 9 from the position data of the memories 3 and 4 stored in the resolution calculation means 9 (step A16).

Further, the above-described resolution measurement will be specifically described with reference to FIGS. FIG. 3 shows FIG.
3A is a diagram showing a state of a recognition target mark in the operation flow shown in FIG. 2A, FIG. 3A shows a state of the target mark in step A8 in FIG. 2, FIG. 3B shows a state of the target mark in step A10 in FIG. 2C shows the state of the target mark in step A13 in FIG. 2, and FIG. 2D shows the state of the target mark in step A15 in FIG.

First, as shown in FIG. 3A, the target mark position (x _S1 .y _S1 ) which has already been taught.
After the stage 5 is moved to [m], image processing is executed, and in step A8, the mark recognition position (x _IP1 , y _IP1 )
[Pixel] and the stage position (x _S1 , y _S1 ) [m] are stored in the memory 1 in the resolution calculation means 9. Next, FIG.
As shown in (b), the stage 5 is moved only in the X-axis direction to the designated position (x _S2 , y _S1 ) [m] that matches the magnification of the recognition device 1, and at step A10 the mark recognition position (x _IP2 , y
_IP2 ) [pixel] and stage position ( _xS2 , _yS1 )
[M] is stored in the memory 2 in the resolution calculation means 9.
From the position data stored in the memories 1 and 2 in the resolution calculating means 9, the approximate rotational offset [rad] and the resolution [m / pixel] with respect to the stage 5 of the recognition device 1 are calculated by the following values in step A11. .

[0026]

(Equation 1) Then, as shown in FIG. 3C, based on the rotation offset [rad] and the resolution [m / pixel] calculated in step A11, the target mark position is set to (1) of the recognition device 1.
28, 128) The stage 5 is moved to the position of [pixel], image processing is executed, and step A1 is performed.
At 3, the mark recognition position (x _IP3 , y _IP3 ) [pixel] and the stage position (x _S3 , y _S3 ) [m] are stored in the memory 3 in the resolution calculation means 9. Further, as shown in FIG. 3D, the rotation offset [r
ad] and the resolution [m / pixel], the stage 5 is moved so that the target mark position is at the position of (−128, −128) [pixel] of the recognition device 1, image processing is executed, and The mark recognition position (x
_IP4, y _IP4) [Pixel] a stage position (x _S4,
y _S4 ) [m] is stored in the memory 4 in the resolution calculation means 9.

Finally, from the position data stored in the memories 3 and 4 in the resolution calculation means 9, the rotational offset [rad] with respect to the stage 5 of the recognition device 1 and X in step A16.
The resolution [m / pixel] in the Y-axis direction is calculated by the following value.

[0028]

(Equation 2)

[0029]

As described above, according to the present invention, the recognition target mark is automatically moved to at least four specified positions in the field of view of the recognition device by the operation of the moving stage, and the recognition target mark is moved at each point. Is recognized by image processing, and the resolution [m / pixel] of the image processing by the recognition device is calculated from the stage position coordinates [m] before and after the movement of each specified position and the mark recognition position coordinates [pixel]. Erroneous operation by the operator does not occur.

Further, for the same reason, there is reproducibility of the positioning accuracy of the stage, and the resolution does not change due to variation in teaching by the operator.

Further, re-teaching by changing the magnification of the type exchange / recognition device or changing the recognition device becomes very simple.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a characteristic portion of a bonding apparatus used for implementing a recognition resolution measuring method of the present invention.

FIG. 2 is a flowchart showing an operation procedure for measuring a resolution in the bonding apparatus shown in FIG. 1;

3 is a diagram illustrating a state of a recognition target mark in the operation flow illustrated in FIG. 2;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 recognition device 2 image processing device 3 recognition position acquisition unit 4 image processing control unit 5 XY stage unit 6 stage control unit 7 stage position acquisition unit 8 stage control unit 9 resolution calculation unit 10 CPU 11 recognition target mark

Claims (6)

(57) [Claims] 1. A recognition resolution measuring method for moving a recognition target mark by a moving stage, recognizing a position of the recognition target mark by using a recognition device, and measuring a recognition resolution of image processing using the recognition device. Moving the recognition target mark within the field of view of the recognition device by four or more points by the operation of the stage, and obtaining the position of the recognition target mark by the number of pixels by the recognition device; and obtaining the position of the recognition target mark. Acquiring the position of the stage at the time of calculating the position of the recognition target mark before and after movement and the position of the stage, and calculating the rotational offset and the recognition resolution of the recognition device with respect to the stage. A recognition resolution measuring method characterized by the following. 2. A bonding apparatus used for performing the recognition resolution measuring method according to claim 1, wherein the recognition target mark is moved by four or more points within a field of view of the recognition apparatus by an operation of the stage. A recognition position acquisition unit that acquires the position of the recognition target mark by the number of pixels by a device; a stage position acquisition unit that acquires the position of the stage when the position of the recognition target mark is acquired; and the recognition target before and after movement. A bonding apparatus comprising at least resolution calculation means for calculating a rotational offset of the recognition device with respect to the stage and a recognition resolution from a position of a mark and a position of the stage. 3. A recognition device for recognizing a recognition target mark, an image processing device for registering and retrieving the recognition target mark, a moving stage unit that moves to allow the recognition device to recognize the position recognition target mark, A stage drive unit that drives and controls the stage unit, and controls the image processing device and the stage drive unit,
A bonding apparatus comprising at least an arithmetic processing unit that calculates a rotational offset and a recognition resolution of the recognition apparatus with respect to the stage from a mark recognition position and a stage position. 4. The method for measuring the recognition resolution of an image processing apparatus in a bonding apparatus according to claim 3, wherein a target mark position already taught is written to a stage target position in a control memory of the arithmetic processing unit. A second stage in which 0 is written in the number of stage movements in the control memory of the arithmetic processing unit; and a third stage in which the moving stage unit is moved to a stage target position by the arithmetic processing unit. A fourth stage in which, after the movement of the moving stage unit is completed, an execution instruction of image processing is output from the arithmetic processing unit to the image processing apparatus; and after the image processing is performed, the arithmetic processing unit determines the mark recognition position and the stage position. A fifth stage in which data is acquired; a sixth stage in which 1 is added to the number of stage movements in the control memory of the arithmetic processing unit; When the number of times is 1, the acquired position data is stored in the first memory in the arithmetic processing unit, and the designated position corresponding to the magnification of the recognition device is written to the stage target position in the control memory of the arithmetic processing unit. A third stage executed from the third stage to the sixth stage after the movement, and when the number of stage movements is 2, the acquired position data is stored in a second memory in the arithmetic processing unit, and the arithmetic processing is performed. At least the approximate resolution is calculated from the position data of the first memory and the second memory stored in the unit, and the position of several pixels from the target mark position is calculated in both the X and Y axis directions using the calculated approximate resolution. An eighth step of executing from the third step to the sixth step after writing to the stage target position in the control memory of the arithmetic processing unit; At one time, the acquired position data is stored in the third memory in the arithmetic processing unit, and the position of minus several pixels from the target mark position in the X and Y axis directions using the approximate resolution calculated in the eighth step. A ninth stage, which is calculated together and written to a stage target position in the control memory of the arithmetic processing unit and then executed from the third stage to the sixth stage; and The acquired position data is stored in a fourth memory in the arithmetic processing unit, and at least the resolution of the image processing is calculated by the arithmetic processing unit from the position data in the third memory and the fourth memory stored in the arithmetic processing unit. 10. A method for measuring a recognition resolution, comprising the steps of: 5. The bonding apparatus according to claim 3, wherein the arithmetic processing unit includes: an image processing control unit that controls the image processing device; a stage control unit that controls the stage driving unit; Recognition position acquisition means for acquiring the recognition position data of the number of pixels from the image processing apparatus, stage position acquisition means for acquiring the position data of the stage unit from the stage driving unit, and data of the mark recognition position and the stage position. A bonding apparatus, comprising: four memories for storing; and a resolution calculating means for calculating a rotational offset and a recognition resolution of the recognition device with respect to the stage from data in these memories. 6. The method according to claim 5, wherein the position of the target mark already taught is written to a stage target position in a control memory of the stage control means. A second step in which 0 is written in the number of stage movements in the control memory of the stage control means, and a third step in which the movement stage section is moved to a target stage position by the stage control means. A fourth stage in which an image processing execution command is output from the image processing control unit to the image processing apparatus after the movement of the moving stage unit is completed; and after the image processing is executed, the recognition position obtaining unit and the stage position obtaining unit. A fifth step in which the data of the mark recognition position and the stage position is obtained by using A sixth stage in which 1 is added to the number of stage movements in the stage, and when the number of stage movements is 1, the acquired position data is stored in a first memory in the resolution calculation means;
A seventh stage for executing from the third stage to the sixth stage after a designated position corresponding to the magnification of the recognition device is written to a stage target position in a control memory of the stage control means; Is 2, the acquired position data is stored in the second memory in the resolution calculating means,
At least an approximate resolution is calculated from the position data of the first memory and the second memory stored in the resolution calculating means. Using the calculated approximate resolution, the position of several pixels from the target mark position is determined on the X and Y axes. An eighth stage in which both directions are calculated and written to the stage target position in the control memory of the stage control means, and thereafter the third stage to the sixth stage are executed; The acquired position data is stored in a third memory in the resolution calculating means,
Using the approximate resolution calculated in the eighth step, the target mark
The position of minus several pixels from the mark position is calculated in both the X and Y axis directions, written into the stage target position in the control memory of the stage control means, and then executed from the third step to the sixth step. 9 steps, and when the number of times of stage movement is 4, the acquired position data is stored in a fourth memory in the resolution calculating means,
And a tenth step in which at least the resolution of image processing by the recognition device is calculated by the resolution calculating means from the position data in the third memory and the fourth memory stored in the resolution calculating means. Recognition resolution measurement method.