JP2003031598A - Method and apparatus for detecting position of rectangular component, and method and apparatus for bonding semiconductor chip using the same - Google Patents

Abstract

(57) [Problem] To accurately detect the position of a rectangular component even if a region having a lower reflectance than another region exists around a corner point of the rectangular component. SOLUTION: Regarding each point detected as four corner points on a chip 35b, angles θa2, θb2, θc formed by lines connecting adjacent corner points to each other.
2, and θd2 are obtained, and the position of the chip 35b is obtained based on the position of the corner point corresponding to the portion where these angles are 90 degrees or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting method and a position detecting device for a rectangular component, and a semiconductor chip bonding method and a semiconductor chip bonding device using them.

[0002]

2. Description of the Related Art Generally, in a semiconductor chip bonding apparatus, a rectangular semiconductor chip (hereinafter simply referred to as "chip") is taken out from a diced wafer and bonded to an island portion which is a mounting position on a substrate. Be done.

In this bonding operation, in order to bond the chip to the island portion with high accuracy, the bonding device is provided with a chip position detecting / correcting device in proximity to the chip extracting device.

This chip position detecting / correcting device has a rotary table 10 as shown in the schematic view of FIG. 6, for example, and a chip 11 taken out by a chip take-out device (not shown) on the rotary table 10. Is placed. Chip 11
Has four corner points A, B, C and D, of which image information a and c including, for example, two corner points A and C having a predetermined diagonal positional relationship are respectively detected by a detection camera (not shown). The positions of both corner points A and C detected based on the captured image information are compared with the normal position by using a known pattern matching method, for example, and the position of the chip in the X, Y, and θ directions relative to the normal position is compared. The shift state is calculated and obtained. The misalignment in the θ direction is corrected by rotating the rotary table 10, and the misalignment in the X and Y directions is carried out by transferring the chip 11 from the rotary table 10 to an island portion of a substrate (not shown) for bonding. It is corrected by correcting the movement amount of the bonding arm.

[0005]

As described above, since the positional deviation state of the chip 11 is calculated based on the position of the corner point of the rectangular chip 11, the position of the corner point can be reliably determined. It is necessary to detect.

By the way, a pattern such as wiring is formed on the surface of the chip 11, and the reflectance of light on the surface of the chip 11 is not uniform. Therefore, as illustrated in FIG. 7, when there is a region 12 having a lower reflectance than other regions around the corner point A of the chip 11, or as shown in FIG. And regions C and C having a lower reflectance than the other regions around C and C.
When there is, there is a possibility that the corner points A and C that should be detected actually may be erroneously detected as A ′ and C ′ as corner points. Then, if the misregistration state of the chip is calculated based on the positions of the erroneously detected corner points A ′ and C ′, the accurate misregistration state cannot be obtained, and as a result, in the bonding apparatus, Highly accurate bonding work cannot be performed.

According to the present invention, even if there is a region having a lower reflectance than the other regions around the corner point of the rectangular part, the position of the rectangular part can be accurately detected. An object of the present invention is to provide a position detecting method and a position detecting device for a shaped part.

Further, according to the present invention, when a rectangular semiconductor chip is bonded to a substrate, even if a region having a lower reflectance than other regions exists around the corner point of the semiconductor chip, the semiconductor chip An object of the present invention is to provide a semiconductor chip bonding method and a semiconductor chip bonding apparatus capable of accurately detecting a position and performing highly accurate bonding.

[0009]

According to a first aspect of the present invention, there is provided a method for detecting a position of a rectangular component, wherein each of the four corner points detected in the rectangular component is a line connecting adjacent corner points. Find each angle to make,
It is characterized in that the position of the rectangular part is obtained based on the position of a corner point corresponding to a portion where the angle is equal to or smaller than a predetermined angle.

According to a second aspect of the present invention, there is provided a position detecting device for a rectangular component, comprising: detecting means for detecting the respective positions of four corner points of the rectangular component; and the position of each corner point detected by the detecting means. , An angle calculation means for calculating and calculating each angle formed by lines connecting adjacent corner points, and a corner point corresponding to a portion of the angles calculated by the angle calculation means that is less than or equal to a predetermined angle And a position calculating means for calculating the position of the rectangular part based on the position of the corner point corresponding to the portion determined to be less than or equal to the predetermined angle.

According to another aspect of the semiconductor chip bonding method of the present invention, regarding each of the four corner points detected on the rectangular semiconductor chip placed on the table, a line connecting the corner points adjacent to each other is formed. Obtain each angle, obtain the position shift state of the semiconductor chip based on the position of the corner point corresponding to the portion where the angle is equal to or less than a predetermined angle, and correct the obtained position shift state while the semiconductor chip of the substrate It is characterized by bonding at the mounting position.

According to a fourth aspect of the present invention, there is provided a semiconductor chip bonding apparatus in which a detecting means for detecting respective positions as four corner points of a rectangular semiconductor chip placed on a table and each of the detecting means detect this. Corresponds to the angle calculation means for calculating each angle formed by the line connecting the adjacent corner points from the position of the corner point, and the part of the angles calculated by the angle calculation means that is less than or equal to the predetermined angle Discriminating means for discriminating a corner point, a positional deviation state calculating means for calculating a positional deviation state of the semiconductor chip on the basis of the position of the corner point corresponding to the portion determined to be equal to or less than a predetermined angle, and this position The semiconductor chip is bonded to the mounting position of the substrate while correcting the positional deviation state calculated by the deviation state calculating means. And having a control means for controlling the up transfer means.

According to the first and second aspects of the present invention, regarding each of the points detected as the four corner points in the rectangular part, the angles formed by the lines connecting the adjacent corner points are obtained. To be Then, the position of the rectangular component is detected based on the position of the corner point corresponding to the portion whose angle is equal to or smaller than the predetermined angle.

According to the third and fourth aspects of the present invention, with respect to each point detected as four corner points in the rectangular semiconductor chip placed on the table,
The angles formed by the lines connecting the corner points adjacent to each other are obtained. Then, the misaligned state of the semiconductor chip is obtained based on the position of the corner point corresponding to the portion where the angle is equal to or less than the predetermined angle, and the misaligned state is corrected so that this semiconductor chip is mounted on the substrate. Bonded.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is applied to a semiconductor chip bonding apparatus will be described below with reference to FIGS.

The semiconductor chip bonding apparatus 30 shown in FIG. 1 is provided with a wafer stage 32 on which a wafer ring 31 is placed. A wafer 34 is attached to the wafer ring 31 via an adhesive sheet 33, and the wafer 34 is diced into individual rectangular semiconductor chips 35 (hereinafter simply referred to as “chips”). .
The wafer stage 32 is placed on an XY table (not shown), and the chips 35 on the adhesive sheet 33 are sequentially positioned at the take-out position.

A chip take-out device 36 is provided near the wafer stage 32. The chip take-out device 36 has a driving device 37. Under the control of a control device 38, the driving device 37 causes the arm 39 to rotate up and down, and the suction nozzle 40 at the tip of the arm 39 is used to move the chip 35 to the adhesive sheet 3.
3, and is mounted on the rotary table 42 of the chip position detection / correction device 41.

The chip position detecting / correcting device 41 has the rotary table 42 as described above. Turntable 42
Is appropriately rotated in the forward and reverse directions under the control of the control device 38, and is configured to hold the chip 35 placed by the arm 39 by a suction force. Further, a detection camera 43 is provided on the turntable 42. The detection camera 43, as described later,
An image including the corner points of the rectangular chip 35 placed on the rotary table 42 is captured, and the captured image is sent to the control device 38.

A bonding head 44 is provided near the chip position detection / correction device 41. The bonding head 44 constitutes a chip transfer means, and the whole of the bonding head 44 is placed on the XY table 45 and the controller 3
8, the horizontal movement of the XY table 45, and the vertical movement and vertical movement of the arm 47 by the drive device 46 cause the arm 4 to move.
The chip 35 on the rotary table 42 is taken out by using the suction nozzle 48 provided at the tip of 7, and is mounted (bonded) on the island portion 50 of the lead frame 49.

The lead frame 49 has an island portion 50.
Each time the chip 35 is bonded to the chip, the chip 35 is transferred by one pitch by a transfer device (not shown).

Now, the above semiconductor chip bonding apparatus operates as follows.

First, when the chips 35 are sequentially positioned at the take-out position by the movement of the wafer stage 32, the chips 35 are sucked and held by the suction nozzle 40 of the arm 39 of the chip take-out device 36 and taken out to the chip position. It is placed on the turntable 42 of the detection / correction device 41. The chip 35 placed on the turntable 42 is
It is held on the rotary table 42 by a suction force.

When the chip 35 is held on the rotary table 42, the detection camera 43 arranged on the rotary table 42.
Thus, the image including the corner point of the chip 37 is captured. The captured image of the detection camera 43 is sent to the control device 38, and the control device 38 processes this image and, based on the processed image, obtains the position deviation state of the chip 35 from the normal position. The position detection of the chip 35 will be described later in detail. Regarding the positional deviation in the angular direction among the positional deviations, the rotary table 42 is rotated so that the positional deviation is corrected. In this way, the tip 35 having the corrected angular deviation
The suction holding by the rotary table 42 is released, the suction holding is performed by the suction nozzle 48 of the arm 47 of the bonding head 44, and the arm 47 is rotated to be transported onto the island portion 50 of the lead frame 49. At this time, the positional deviation in the XY directions among the previously determined positional deviations is corrected by the movement control of the XY table 45 on which the bonding head 44 is mounted, whereby the chip 35 remains in the positional deviation state. It is transported to the island portion 50 and bonded.

Next, the position detection of the chip 35 held on the rotary table 42 will be described.

The chips 35 held on the rotary table 42 are all rectangular in shape, and the angles of the corner points are all 90 degrees or less. However, as shown in FIG. 2, the chips 35a having a uniform surface reflectivity. As shown in FIG. 3, a chip 35b in which a region 51a having a lower reflectance than the other regions exists around the corner point A, and as shown in FIG. Chip 3 in which regions 51a and 51c each having a lower reflectance than the other regions are present in either periphery
Position detection for each of 5c will be described based on the flow of FIG.

First, the position detection of the chip 35a having a uniform surface reflectance shown in FIG. 2 will be described.

First, the tip 35a is attached to the rotary table 4.
When held at 2, the detection camera 43 captures images including the corner points of the chip 35a at the four corners, respectively, and the control device 38 recognizes the positions recognized as the respective corner points based on the captured images. It is detected (step S1). Therefore, the detection camera 34 and the control device 38 here constitute a detection means.

For this detection, the detection camera 43 is fixed and the rotary table 42 is rotated by 90 degrees, and each time the detection camera 43 captures the respective images a to d including the corner points A to D. . Then, the captured image is sent to the control device 38, where it is subjected to image processing, and compared with a reference image registered in advance in the control device 38 by a known pattern matching method, and each point recognized as a corner point. The position coordinate of is calculated. Note that when capturing each image including the four corner points A to D by the detection camera 43,
The detection camera 43 may be moved so that the detection camera 43 is sequentially positioned at a position facing each corner point.

In this way, the position coordinates (x1, y1) of the corner point A recognized and detected, the position coordinates (x2, y2) of the corner point B, and the position coordinates (x3, y3) of the corner point C are detected. , The position coordinates of the corner point D (x4, y
4) is obtained, from the position information, in the control device 38, the respective angles θa1, θb1, θc1 formed by the line connecting the corner points adjacent to each other (in FIG. 2, overlapping the respective sides) are formed. , Θd1 are calculated and obtained (step S2). Therefore, the control device 38 here is
Functions as an angle calculation means.

Next, the control device 38 obtains the number of angles that are 90 degrees or less among the calculated angles, and determines whether the number is 2 or more (step S3). The case of FIG. 2 corresponds to the case where the correct four corner points of the rectangular chip 35a are recognized, and therefore it is determined that there are four angles of 90 degrees or less. Therefore, the process proceeds to step S4 in the flow of FIG.

In step S4, the control device 38 determines whether or not there is a pair of corner points corresponding to the two or more angles of 90 degrees or less determined in step S3 and having a diagonal positional relationship with each other. Is determined. In the case of FIG.
It is determined that the two sets of corner points A and C and B and D have a diagonal positional relationship with each other, and the process proceeds to step S5. The reason for selecting the corner points having the diagonal positional relationship is that the distance between the corner points having the facing positional relationship is longer than the distance between the adjacent corner points, and the misalignment state is detected accordingly. Is improved in accuracy.

In step S5, the control device 38 selects a set of corner points having a diagonal positional relationship. When there is only one pair of corner points having a diagonal positional relationship, that pair is uniquely determined, but in the case of FIG. 2, the two pairs have a diagonal positional relationship as described above. In this case, in the present embodiment, the corner points A and C having the facing positional relationship are selected in advance by programming.
In addition, through steps S3 to S5, the control device 38 here functions as a determination unit.

Next, in step S6, the control device 38 determines the position of the center point of the diagonal line 52a connecting the corner points A and C from the detected position coordinates of the corner points A and C, for example, from the following equation. Ask. X-coordinate = (x1 + x3) / 2 Y-coordinate = (y1 + y3) / 2 Then, the position of the center point of the diagonal line calculated and calculated is calculated as chip 3
The center position P1 of 5a is set, and the angle of the diagonal line 52a connecting the corner points A and C with respect to the X-axis is calculated to be recognized as the diagonal angle θ1 of the tip 35a.

Next, in step S7, step S
The center position P1 of the chip 35a and the diagonal angle θ1 obtained in 6 are compared with the reference position and the reference angle registered in advance in the control device 38, and the position deviation state (ΔX, ΔY, Δθ) is obtained. Therefore, the control device 38 here functions as a positional deviation state calculation means.

This completes the process of detecting the position of the chip 35a and determining the displacement state. Regarding the positional deviation in the angle (θ) direction, the rotary table 42 is rotated so as to correct the positional deviation, and the positional deviation in the XY directions is performed by the X on which the bonding head 44 is mounted.
The correction by the movement control of the Y table 45 is as described above.

Next, as shown in FIG. 3, the position detection of the chip 35b having the area 51a having a lower reflectance than the other areas around the corner point A will be described.

First, in step S1, each image including the four corners of the chip 35b is captured similarly to the case of the chip 35a, and the position recognized as the corner point is detected based on each captured image.

In the case of the chip 35b shown in FIG. 3, a region 51a having a lower reflectance than the other regions around the corner point A is formed.
Therefore, regarding the corner point A, the description will proceed assuming that the corner point A ′ (x1 ′, y1 ′) has been detected by erroneous detection.

In this case, in step S2, the angles θa2, θb2, θc2 formed by the lines connecting the adjacent corner points of the four recognized corner points, respectively,
Although θd2 is obtained, the three angles θb2, θc2, and θd2 are 90 degrees or less, and θa2 is 90 degrees or more.

Therefore, in step S3, the result is "Y", and among the angles determined to be 90 degrees or less in step S4 as well, the corner points B and D respectively corresponding to θb2 and θd2 are in a diagonal positional relationship with each other. Is set to "Y", and in step S5, since only one pair has a diagonal positional relationship, corner points B and D are selected.
Therefore, after this, from the position coordinates of these corner points B and D,
Similarly to the case of the tip 35a, the center position P2 of the tip 35b and the diagonal line 5 of the tip 35b are determined in step S6.
The angle θ2 of 2b with respect to the X axis is recognized. Then, in step S7, the center position P of the tip 35b is
2 and the diagonal angle θ2 are compared with the reference position registered in advance in the control device 38 and the reference angle, and the tip 35b
The positional deviation state from the normal position of is determined.

Finally, as shown in FIG. 4, a chip 3 in which regions 51a and 51c having a lower reflectance than the other regions are present around both corner points A and C having a diagonal positional relationship.
The position detection of 5c will be described.

First, in step S1, each image including the four corners of the chip 35c is captured similarly to the case of the chip 35a, and the position recognized as the corner point is detected based on each captured image.

In the case of the chip 35c shown in FIG. 4, a region 5 having a lower reflectance than the other regions around the corner points A and C.
Due to erroneous detection, corner point A ′ (x1 ′, y1 ′) is obtained for corner point A, and corner point C ′ (x3 ′, y is obtained for corner point C due to the presence of 1a and 51c.
3 ') has been detected and the description will proceed.

In this case, in step S2, the angles θa3, θb3, θc3 formed by the lines connecting the adjacent corner points of the four recognized corner points respectively,
θd3 is calculated. Below 90 degrees are two θb3 and θd3, and θa3 and θc3 are 90 degrees or more.

Therefore, in step S3, it becomes "Y", and also in step S4, the corner points B corresponding to the angles .theta.b3 and .theta.d3 determined to be 90 degrees or less, respectively.
And D have a diagonal positional relationship with each other, so that the result is “Y”. In step S5, since only one set has a diagonal positional relationship, corner points B and D are selected. Therefore,
In the same manner as in the case of the chip 35b, the positional deviation state of the chip 35c from the normal position is finally obtained.

The above three chips 35a, 35b, 35
Although the description has been made by taking c as an example, 90
Even if it is determined that there are no more than two angles equal to or less than 90 degrees, or even if it is determined that the two angles are less than 90 degrees, step S
When it is determined that the corner points corresponding to the two angles are not in the diagonal positional relationship in 4, the proper diagonal line cannot be obtained, and therefore, the position cannot be detected (NG). (Step 9).

According to the embodiment described above, the images including the four corner points of the chips 35 placed and held on the rotary table 42 are respectively captured, and the respective corners recognized as the corner points are acquired. Regarding the point, the position of the chip 35 is finally detected based on the position of the corner point corresponding to the portion where the angle formed by the lines connecting the adjacent corner points is 90 degrees or less. Even if the chips 35b and 35c have the uneven reflectance on the surface like the above, and particularly the chips 35b and 35c having the regions 51a and 51c having a lower anti-oblique ratio than the other regions around the corner point, the positions of the chips 35a and 35c are accurately determined. Can be detected. When applied to the semiconductor chip bonding apparatus 30, highly accurate bonding can be performed.

In the above embodiment, the displacement of the chip 35 is corrected by the rotation control of the rotary table 42 and the movement control of the XY table 45 on which the bonding head 44 is mounted. By mounting 42 on the XY table, the rotary table 42 is configured to be movable in the XY directions in addition to being rotated, and all the positional deviations of the chip 35 in the X, Y, and θ directions are chip position detection / correction devices. It may be corrected in.

Further, in the above-described embodiment, as the step of determining the corner point used for position detection, it is determined in step S3 whether the angle formed by the line connecting the adjacent corner points is 90 degrees or less. The width is not necessarily limited to 90 degrees, and a certain width may be allowed.

[0050]

According to the present invention, even if there is a region having a lower reflectance than the other regions around the corner point of a rectangular part, the position of the rectangular part can be accurately detected. You can

Further, in bonding a rectangular semiconductor chip to a substrate, even if there is a region having a lower reflectance than the other regions around the corner point of the semiconductor chip, the position of the semiconductor chip can be accurately determined. Detected in
Highly accurate bonding can be performed.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a semiconductor chip bonding apparatus to which the present invention is applied.

FIG. 2 is a schematic diagram showing a position detection state of a chip to which the present invention is applied.

FIG. 3 is a schematic diagram showing a position detection state of a chip to which the present invention is applied.

FIG. 4 is a schematic diagram showing a position detection state of a chip to which the present invention is applied.

FIG. 5 is a flow chart of chip position detection to which the present invention is applied.

FIG. 6 is a schematic diagram showing a position detection state of a conventional chip.

FIG. 7 is a schematic diagram showing a position detection state of a conventional chip.

FIG. 8 is a schematic view showing a position detection state of a conventional chip.

[Explanation of symbols]

30 Semiconductor chip bonding equipment 34 wafers 35 Semiconductor Chip (Chip) 38 Control device 41 Chip position detection / correction device 42 turntable 43 Detection camera 44 bonding head 45 XY table 48 suction nozzle A corner point B corner point C corner point D corner point

Claims (4)

[Claims] 1. For each point detected as four corner points in a rectangular part, each angle formed by lines connecting adjacent corner points to each other is obtained, and the angle corresponds to a portion equal to or less than a predetermined angle. A method for detecting the position of a rectangular part, wherein the position of the rectangular part is obtained based on the position of the corner point. 2. A detection means for detecting respective positions of four corner points of a rectangular part, and a line connecting the corner points adjacent to each other from the position of each corner point detected by the detection means. An angle calculation unit that calculates and obtains each angle formed, a determination unit that determines a corner point corresponding to a portion of the angles calculated by the angle calculation unit that is less than or equal to a predetermined angle, and this determination unit is less than or equal to the predetermined angle. And a position calculating means for calculating the position of the rectangular component based on the position of the corner point corresponding to the portion determined to be. 3. For each point detected as four corner points in a rectangular semiconductor chip placed on a table, respective angles formed by lines connecting adjacent corner points are obtained, and the angles are A position deviation state of the semiconductor chip is obtained based on a position of a corner point corresponding to a portion having a predetermined angle or less, and the semiconductor chip is bonded to a mounting position of a substrate while correcting the obtained position deviation state. Semiconductor chip bonding method. 4. A detecting means for detecting respective positions of four corner points of a rectangular semiconductor chip mounted on a table, and the corner points detected by the detecting means are adjacent to each other. An angle calculation means for calculating and calculating each angle formed by a line connecting the corner points, and a determination means for judging a corner point corresponding to a portion of the angles calculated by the angle calculation means which is equal to or less than a predetermined angle. A positional deviation state calculating means for calculating a positional deviation state of the semiconductor chip based on the position of a corner point corresponding to a portion determined by the determining means to be less than or equal to a predetermined angle; and a positional deviation calculated by the positional deviation state calculating means. Control means for controlling the semiconductor chip transfer means so as to bond the semiconductor chip to the mounting position of the substrate while correcting the state. A semiconductor chip bonding apparatus according to claim.