JP2003077955A - Bonding method and bonding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bonding method for accurately detecting a chip at a front-end position to bond all chips without fail. SOLUTION: The method which sequentially takes out multiple chips formed on a semiconductor wafer 5 and bonds them on a substrate 25 comprises steps of imaging a plurality of chips on the semiconductor wafer; recognizing the plurality of chips from the image acquired by the imaging step; determining whether the recognized plurality of chips have any defect thereon; picking up the chips for bonding on the substrate; and carrying the chips while controlling such that chips determined to have a defect based on the determining step are omitted before being carried.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding method and a bonding apparatus for bonding a chip which is an electronic component to a substrate.

[0002]

2. Description of the Related Art A flip chip bonder is known as a bonding device for bonding a chip made of a semiconductor wafer as an electronic component to a substrate. The flip chip bonder uses a wafer recognition camera to capture an image of the semiconductor wafer that has been diced on the wafer stage and supplied.
The displacement of the chip is detected from the imaging result, the pickup position is corrected, and a predetermined chip is picked up by the pickup reversing tool.

Although there is a variation of 200 to 300 μm at the time of picking up by the pick-up reversing tool, the chip is reversed as it is by the pick-up reversing tool and transferred to the bonding tool of the bonding head. Then, the chip recognition camera images the chip, and the positional deviation of the chip is detected from the imaging result.

The substrate on the bonding stage is imaged by a substrate recognition camera, and the displacement of the substrate is obtained from the imaged result. The correction amount of the bonding position is obtained from the result of the positional deviation between the substrate and the chip, and the chip is bonded to the substrate after correcting the bonding position.

[0005]

By the way, a chip for forming a SAW (surface acoustic wave) device or the like is
Since the size is as small as 1 to 2 mm square, it is necessary to increase the magnification of the wafer recognition camera.

However, the semiconductor wafer supplied to the wafer stage has variations in the positions in the X, Y, and θ directions to be attached to the sheet, so that the actual starting position of the chip is different from the starting position of the previously taught chip. Is XY
It may be offset by several rows or columns in the direction. As a result, the chips of the semiconductor wafer supplied to the wafer stage may be left behind.

Further, if the position of the semiconductor wafer supplied to the wafer stage in the θ direction is deviated, even if the chip at the leading position can be taken out, the wafer is recognized as the taken-out position moves in the X direction or the Y direction. Sometimes the camera cannot recognize the chip.

On the other hand, when the chip transferred from the pick-up reversing tool to the bonding tool is bonded to the substrate, the bonding tool is lowered to a predetermined height position at a high speed in order to shorten the tact time, and the speed is lowered from that position. I am trying to lower it at a constant speed. The height position at which the bonding tool is switched from high-speed descent to constant-speed descent, that is, the search start height is usually set at a position where the chip is about 0.5 mm above the substrate. However, the substrate supplied to the bonding stage may be deformed due to the undulation of the material, the influence of heat, or the like. Therefore, the search start height needs to be set to a height equal to or more than the maximum deformation amount of the substrate. As a result, there is a considerable difference in the search start height depending on the amount of deformation of the substrate, so that the takt time for bonding at the place where the search start height is high becomes long, which may cause a decrease in productivity. It was

If the search height is lowered to shorten the tact time, the chip may come into contact with the substrate during high-speed descent in a portion where the deformation amount of the substrate is large. further,
The deformation of the substrate causes variations in the search height, which may increase variations in the impact generated when the chip contacts the substrate depending on the bonding position.

It is an object of the present invention to provide a chip bonding method and a chip bonding apparatus which can surely bond even a small chip to be bonded.

[0011]

According to a first aspect of the present invention, in a bonding apparatus for sequentially taking out a large number of chips formed on a semiconductor wafer and bonding them to a substrate, a plurality of chips including at least mirror chips of the semiconductor wafer are provided. A bonding apparatus comprising: an image pickup means for picking up an image; and an image processing means for detecting a position of a leading chip bonded to the substrate from an image obtained by the image pickup means.

According to a second aspect of the present invention, in a bonding method in which a large number of chips formed on a semiconductor wafer are sequentially taken out and bonded to a substrate, an imaging step of imaging a plurality of chips of the semiconductor wafer, and an imaging step A recognition step of recognizing a plurality of chips from the obtained image; a judgment step of judging whether or not the recognized plurality of chips have a defective mark; a step of picking up the chips for bonding to a substrate; And a chip feeding step of controlling the semiconductor wafer to be placed by skipping the chip having the defective mark based on the above.

According to a third aspect of the invention, in a bonding apparatus for sequentially taking out a large number of chips formed on a semiconductor wafer and bonding them to a substrate, an image pickup means for picking up an image of a plurality of chips of the semiconductor wafer, and the image pickup means are provided. Image processing means for recognizing the positions of the plurality of chips from the obtained image and determining whether the recognized plurality of chips have a defective mark; a step of picking up the chips to bond them to the substrate; The bonding apparatus is characterized in that it includes a chip feeding step of controlling the semiconductor wafer to be skipped by skipping the chip having the defective mark based on the step.

According to a fourth aspect of the present invention, the step of lowering the bonding tool holding the chip to a predetermined position at a high speed and the step of lowering the bonding tool lowered to the predetermined position at a constant speed to bond the chip to the substrate are performed. In a bonding method for bonding a plurality of chips to the substrate by repeating the above step, the position for lowering the bonding tool at a constant speed is set to a predetermined dimension higher than the previous bonding position. On the way.

According to a fifth aspect of the present invention, in a bonding method of holding a chip in a bonding tool and bonding the chip to a substrate by the bonding tool, an image of an end face of the reference bonding tool holding the chip is picked up and an image thereof is taken. The process of teaching
A step of capturing an image of an end surface of a bonding tool for bonding the chip, and comparing the image with an image of an end surface of a teaching reference bonding tool;
Controlling the coordinates of the bonding tool when the chip is received from the reversing tool based on the comparison of two images.

According to a sixth aspect of the present invention, in a bonding apparatus in which a chip is held by a bonding tool and the chip is bonded to a substrate by the bonding tool, an end face of the reference bonding tool which holds the chip is imaged, and an image thereof is taken. And an image pickup means for picking up an image of the end face of the bonding tool for bonding the chip, and two images picked up by this image pickup means are compared, and bonding is performed when the chip is received from the reversing tool based on the comparison. And a control means for controlling the coordinates of the bonding tool at that time.

According to a seventh aspect of the present invention, in a bonding apparatus for bonding a chip provided on a supply table to a substrate by a bonding tool, a pick-up reversing tool that takes out the chip from the supply table, reverses it, and transfers it to the bonding tool is provided. However, in this bonding apparatus, the end face of the pickup reversing tool for holding the chip is coated with a material that does not give off a metallic luster.

According to an eighth aspect of the present invention, in a bonding method for bonding a chip held by a bonding tool to a substrate, a first recognition point of the chip and a first recognition point of the substrate are simultaneously imaged. An imaging step, a second imaging step of simultaneously imaging the second recognition point of the chip and a second recognition point of the substrate, and the chip and the substrate imaged by the first and second imaging steps. The step of positioning the chip on the basis of the coordinates of the recognition point and bonding the chip to the substrate.

According to a ninth aspect of the invention, in a bonding apparatus for bonding a chip held by a bonding tool to a substrate, the first recognition point of the chip and the first recognition point of the substrate are imaged at the same time, and then the Imaging means for simultaneously imaging the second recognition point of the chip and the second recognition point of the substrate, and control means for positioning the chip based on the imaging result of the imaging means and bonding the chip to the substrate. And a bonding apparatus including:

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIGS. 1 to 17 show a first embodiment of the present invention.

FIG. 1 shows a mounting apparatus, which is equipped with a wafer stage 1 as a supply unit for electronic components. The wafer stage 1 has an XY table 2 and a θ table 3 which are sequentially provided on a base 2a, and a semiconductor which is divided into a large number of chips 4 as electronic components on the θ table 3 and is attached to a sheet (not shown). The wafer 5 is placed.

The chip 4 is taken out by the pickup reversing unit 7. The pickup reversing unit 7 has an L-shaped pickup reversing tool 8. The pick-up reversing tool 8 has a nozzle 9 for vacuum-sucking the chip 4 at the tip portion, and a base end portion of the mounting portion 12 provided on the Z table 11 from a state shown by a solid line to a state shown by a chain line in FIG. That is, it is attached so as to be rotated and driven in the range of 180 degrees in the horizontal direction. Z table 11 above
Are driven in the Z direction along the Z guide 13.

The semiconductor wafer 5 is picked up by a wafer recognition camera 14 arranged above the wafer stage 1. The chip 4 picked up by the pickup reversing tool 8 is positioned based on the image pickup signal of the wafer recognition camera 14. That is, the θ table 3 is positioned in the X, Y and θ directions.

FIG.
Pickup inversion tool 8 inverted to the state shown by the solid line
Is picked up by the hand-over recognition camera 15. The chip 4 imaged by the transfer recognition camera 15 is
It is delivered to the bonding tool 17 of the bonding head 16 based on the imaging result of the delivery recognition camera 15.

The outer diameter of the bonding tool 17 is equal to or slightly smaller than the outer diameter of the chip 4 so that the chip 4 can be attracted and held in a stable state by the bonding tool 17. It is set with the size. In this embodiment, it is set slightly larger.

The bonding head 16 has a base 18
Have. An X table 19 is provided on the base 18 so as to be driven in the X direction as indicated by an arrow in FIG. A Y table 21 is provided on the X table 19 so as to be driven along the Y direction. A Z table 22 is provided on the Y table 21 so as to be driven in the Z direction. The Z table 22 is provided with a θ table 23, and the θ table 23 is provided with the bonding tool 17.

Therefore, the bonding tool 17
Can be driven in the X, Y, Z and θ directions.

The chip 4 delivered to the bonding tool 17 is imaged by the component recognition camera 24. Further, the board 25 on which the chip 4 attracted to the bonding tool 17 is mounted is imaged by the board recognition camera 26.

The substrate 25 is placed on a bonding stage 27 which can be driven in the X direction. The board recognition camera 26 is provided on a Y table 29 provided on a guide 28 along the Y direction so as to be drivable along the Z direction. Therefore, the substrate recognition camera 26 can be driven in the X, Y, and Z directions relative to the substrate 25 on the bonding stage 27.

FIG. 2 is a block diagram of the control system. In FIG.
Is the main controller. The wafer recognition camera 14, the delivery recognition camera 15, and the component recognition camera 2 are connected to the main controller 31 via the image recognition control unit 32.
4 and the board recognition camera 26 are connected. An image pickup signal from each camera is processed by the image recognition control section 32 and input to the main controller 31.

Further, the main controller 31 includes a wafer stage controller 33 for controlling the drive of the wafer stage 1, a pickup controller 34 for controlling the drive of the pickup reversing unit 7, and the bonding stage 2.
A bonding stage controller 35 that controls the driving of the substrate recognition camera 7 and a camera movement controller 36 that controls the driving of the substrate recognition camera 26 are connected.

3 (a) and 3 (b) show a state in which the tip 4 is adsorbed by the nozzle 9 of the pickup reversing tool 8. The nozzle 9 is made of metal such as stainless steel and is attached to the adsorption surface 9a. Is coated with an oxide 9b such as ceramics.

By coating the suction surface 9a of the nozzle 9 with ceramic, it is possible to reduce the reflectance of the suction surface 9a and improve wear resistance. As described above, by forming the suction surface of the nozzle 9 and its vicinity by using a material having no metallic luster or a material having a lower reflectance than the metal surface, the chip 4 sucked by the nozzle 9 is shown in FIG. Even if a part of the suction surface 9a is exposed by being absorbed by being displaced from the suction surface 9a as indicated by a chain line in a), since the reflectance of the suction surface 9a is low, the chip is detected by the transfer recognition camera 15. The recognition of 4 can be surely performed.

The bonding tool 17 is regularly
Alternatively, if it is damaged, it is replaced with a new one. When the bonding tool 17 is replaced, the position of the end surface (suction surface) of the replaced tool in the XY direction changes due to various conditions, which may cause an error in the bonding position of the chip 4 to the substrate 25.

Therefore, as shown in FIG. 4A, the bonding tool 17 serving as a reference is imaged in advance by the component recognition camera 24, and two corners 17a of the tool 17 are detected from the image.
Teaching the XY coordinates of 17b.

After the bonding tool 17 is replaced, as shown in FIG. 4B, the tool 17 is imaged by the component recognition camera 24, and the XY coordinates of the two corners 17a and 17b of the tool 17 are taken from the image. Is compared with the XY coordinates of the corners 17a and 17b of the taught tool 17. Then, the coordinates when the chip 4 is received from the nozzle 9 are corrected according to the difference between the compared values.

Accordingly, even if the XY coordinates of the end surface of the exchanged tool 17 are displaced by exchanging the bonding tool 17, it is possible to prevent an error in the position of the chip 4 with respect to the tool 17 due to the displacement. be able to.

The semiconductor wafer 5 supplied to the θ table 3
Is divided into a large number of chips 4 and attached to a sheet (not shown). When the semiconductor wafer 5 is attached to a sheet, if there are variations and the size of the chip 4 becomes small, the position (leading position) of the chip 4 first taken out from the θ table 3 by the pickup reversing tool 8 may be displaced. .

Then, the chip 4 at the head position is recognized as follows. First, FIGS. 5 to 7 are flowcharts showing teaching. FIG. 5 is a flowchart for teaching the size of the chip 4 and the pitch of the chip 4. In S ₁ , as shown in the image G ₁ in FIG. Multiple chips 4
Image. At this time, the image G ₁ includes at least the mirror chip 4a on which the circuit pattern is not formed.

Next, S_TwoImage G₁Along the X direction above
Coordinates TP of two points of a line segment₁(X₁， _Y1), TP_Two(X
_Two, Y_Two) And enter the semiconductor wafer from the coordinates of these two points.
5 for the coordinate system in the image recognition control unit 32 in the X direction
The tilt θ is corrected to 0. FIG. 8B shows an image G
₁, The inclination θ of the semiconductor wafer 5 is corrected to 0 °.
Shows the closed state.

In S ₃ , as shown in FIG. 9, the coordinates CP ₁ (X ₁ , Y) at the upper left of the chip 4 at the head position in the image G ₁ are set.
₁ ) is registered, and in S ₄ , the lower right coordinate CP of the chip 4 is registered.
₂ (X ₂ , Y ₂ ) is registered. In S ₅ , the upper left coordinate CP ₃ (X
₃ and Y ₃ ) are registered.

By registering the coordinates of the three points as described above, the size Xs of the chip 4 in the X direction, the size Ys in the Y direction, and the chip pitch Xp in the X direction are registered, as shown in the image G ₂ in FIG. , Y-direction chip pitch Yp is calculated.

[0044] Figure 6 is a flowchart for registering the recognition pattern of the chip recognition, a plurality of chips 4 (mirror chips 4a at any position by a semiconductor wafer recognition camera 14 as an image G ₃ shown in FIG. 10, S ₆ (Including) is imaged. In S ₇ , the inclination θ of the semiconductor wafer 5 in the X direction (short side direction of the chip 4) with respect to the raised pure position is corrected as in the case of the flowchart of FIG.

S₈Shows the external corners of chip 4 to be registered.
Top left coordinate TCP₁(X₁, Y ₁) Is registered, S
₉Then, the lower right coordinate TCP showing the outer corner of the chip 4_Two(X
_Two, Y_Two) Is registered. On the other hand, S₁₀Then the tip
The shape of the whole 4 is registered as a recognition pattern. to this
Therefore, in the image showing the entire chip 4,
The coordinates of the corners of the shape can be recognized.

[0046] Figure 7 is a flowchart of the teaching of recognition patterns for head position detection of the tip 4, the wafer recognition camera 14, as shown in the image G ₄ in the S ₁₁ FIG. 11 (a) in the vicinity of the top of the semiconductor wafer 5 Mirror A plurality of chips 4 including the chip 4a are collectively imaged.

[0047] As with the teaching of FIG. 5, S _12, theta correction of the semiconductor wafer 5 is performed. S ₁₃
Then, the upper left coordinate FCP ₁ (X ₁ , Y ₁ ) indicating the outer corner of the leading chip 4 which the person performing teaching wants to set as the take-out start position is registered, and in S ₁₄ , the outer corner of the chip 4 is indicated. Lower right coordinates FCP ₂ (X ₂ , Y ₂ )
Is registered.

_Meanwhile, the _{S 15} is the top position recognition patterns are registered. The head position recognition pattern has a shape that does not cause erroneous detection, for example, the head chip 4b as shown in FIG.
The image of the region 4a including the four mirror chips on the left side of is captured and registered as a recognition pattern. As a result, the relative position of FCP ₁ or FCP ₂ with respect to the center position of the image showing this recognition pattern is calculated.

After the teaching is completed in this way, a case where the chip is actually taken out from the wafer stage 1 by the pickup reversing tool 8 will be described. In that case, the steps of θ correction of the semiconductor wafer 5, detection of the start position of the semiconductor wafer 5, detection of the start position chip 4 and detection of a defective chip are performed.

First, as shown in FIG. 12, in S ₁₆ , a plurality of chips 4 near the center of the semiconductor wafer 5 are imaged as shown by an image G ₅ in FIG. 13, and a binarized lower image is shown in FIG. Incorporated in the main controller 31 shown. In S ₁₇ , the tilt angle Δθ with respect to the coordinate system of the image recognition control unit 32 in the long side direction of the chip is detected from the image G ₅ , and in S ₁₈ , the θ table 3 is rotated based on the Δθ to rotate the semiconductor wafer 5.
Primary correction of the inclination of.

At S ₁₉ , as shown in FIG.
The table 3 is replaced with the XY table 2 by the chip pitch Yp.
The chip 4 (+ Y) located at the end in the + Y direction is detected by moving in the -Y direction in several pitches. In S ₂₀ theta table 3 is moved divided into the + Y direction in several pitches each chip pitch Yp by the XY table 2 chip 4 (+ Y) to be in the -Y direction end located on the same line chip 4 (-Y) To detect. At this time, when the chip 4 cannot be detected in the Y direction as shown in S ₂₁ , the θ table 3 is returned to the original position, and then the chip 4 in the X direction is detected as shown in S ₂₂ , Chip 4 (+ Y) and chip 4
Substitute for (-Y).

[0052] In _{S 23,} as shown in FIG. 14 (b),
The center position of the chip 4 (+ Y) and the chip 4 (-Y),
That is, a pair of chip center positions (X1, Y1), (X2,
The tilt angle Δθ ₁ of the semiconductor wafer 5 with respect to the coordinate system of the image processing control unit 32 is detected from Y2), and in S ₂₄ , the θ stage 3 is operated to correct the tilt angle Δθ ₁ to zero.

If the tilt angle of the semiconductor wafer 5 is only roughly adjusted in S ₁₈ , the accuracy cannot be obtained, and if the semiconductor wafer 5 is tilted too much only by finely adjusting it in S ₂₄ , chips at one end and the other end in the Y direction are chipped. When detecting 4, chip 4 in a different row
May be erroneously detected. By performing both the coarse adjustment and the fine adjustment, the tilt angle Δθ ₁ of the semiconductor wafer 5 can be adjusted reliably and precisely.

In S ₂₅ , the θ table 3 is moved in the XY directions so that the head position of the semiconductor wafer 5 is set to the wafer recognition camera 14.
Go to be within the field of view, the semiconductor in S ₂₆ the wafer 5
A region 4a including four mirror chips and a region including a plurality of chips 4 near the beginning of the image are imaged by the wafer recognition camera 14 and image matching is performed with the pattern 4a registered in the image recognition, which corresponds to the pattern 4a in this image. The amount of deviation in the XY directions with respect to the coordinate system of the image recognition processing unit 32 of the leading chip 4b is detected. With identifying the leading tip 4b using center coordinates and _FCP 1, FCP ₂ in the area in S _27, operating the XY stage 2 to move the θ table 3, to correct the head position of the chip 4. This completes the positioning of the leading chip 4b.

As described above, with respect to the semiconductor wafer 5 having a plurality of newly-loaded micro-sized chips 4 formed therein, the chip to be picked up first can be surely detected by image recognition. like,
It is possible to eliminate the deviation of the pickup start position that occurs when performing the prospective feed using the chip pitch, and it is possible to automatically start bonding without omission. At this time, while recognizing a specific portion on the periphery of the semiconductor wafer by the recognition pattern including the mirror chip,
By setting the tip having a relative positional relationship with respect to this specific portion that has been taught in advance as the pickup start position, it is possible to reliably search for the pickup start position.

Next, the operation during bonding shown in the flowchart of FIG. 15 will be described in detail.

[0057] First, in S _28, so that chip to be picked up comes to the vicinity of the origin of the coordinate system of the image processing control unit 32 (near the monitor screen center), XY table 2
To control. The feed control at this time is performed using the chip pitches Xp and Yp. At this time, the screen shown in FIG.
The image shown in G ₆ of ₆ appears.

_Next, in _{S 29,} based on the recognition range determined in advance, the 3-chip 4-2,4-3,4-4 adjacent including chips 4-1 near the monitor center, _{pre-S 10} Pattern matching is performed using the recognition pattern on the chip that was taught at.

[0059] In S _30, the center coordinates of the site corresponding to the portion that matches the recognition pattern obtained as a result of the pattern matching of S _29, taking in the result storage area in the memory space.

[0060] In S _31, the pitch of the result storage center coordinates taken into areas, chip pitch Xp (if recognition range is long in the Y-direction chip pitch Yp) to be searched for in the vicinity of integral multiples of. As a result, a matching result having a coordinate value that is not near an integral multiple of the chip pitch is not considered as a pickup target.

[0061] _{Subsequently,} in _{S 32} performs the defective chip detection. The semiconductor wafer has already been clarified by inspection as to whether the chips are good or bad, and defective chips are loaded in the bonding apparatus with marking. This marking is extracted by image processing,
The marked chip is removed from the pick-up target. First, the image within the recognition range is binarized, and the black circle image B “●” is detected in this. When the black circle image B image is detected, the presence or absence of this black circle image B within the range of the chip size assumed from the coordinates of the taught chip is determined, and the center coordinates obtained in S ₃₁ are determined. Store in the result storage area as you would. If present, it is not considered for pickup.

In S ₃₃ , the chips corresponding to the central coordinates except the central coordinates which are not considered as the object of pickup in S ₃₁ and S ₃₂ are sent to the origin of the coordinate system of the image processing control unit 32, and Fine positioning of the XYθ3 axes is performed by using the taught chip image, and the bonding operation is performed.

S₃₄In, S₃₁And S₃₂To
As a result of the determination, S₃₃Chi picked up at
In addition to the chips, there are chips to be bonded.
To see if As a result, there is another problem within the recognition range.
If you have a chip that you can cue up, image that tip
It is sent to the origin of the coordinate system of the processing control unit 32, and it moves within the recognition range.
If you do not have a chip that can be
Place the contacting chip near the origin of the coordinate system of the image processing control unit 32.
Send it to. That is, G shown in FIG. ₆Is
When displayed on Nita, chip 4-1 is S₃₃At
Chip 4 after being picked up and bonded
-3 is sent to the center of the monitor by driving the XY table
It S₃₄After the step₂₉Repeat the following steps
By doing so, only good chips are bonded.
It will be.

As described above, since the chip size and the chip pitch are registered, the recognition pattern used for detecting the head position of the chip is registered, and the recognition pattern for detecting the head position chip is registered, the head of the semiconductor wafer 5 is registered. A normal chip can be picked up by the pick-up reversing tool 8 without being left behind from the chip 4 at the position.

Moreover, the chip 4 to which the black pixel B, which is a defective mark, is attached can be discriminated by image recognition, and can be prevented from being picked up by the pickup reversing tool 8.

When the chip is image-recognized and the chip is positioned with respect to the pick-up position of the pick-up tool of the bonding apparatus (the origin of the coordinate system of the image processing control unit in the above embodiment), the chip is at the pick-up position. Instead of recognizing only the chip, multiple chips adjacent to this chip are recognized at the same time, pattern matching is performed uniformly, and it is distinguished from those that are not to be bonded, and after bonding, Since it is possible to control the feed by skipping those that are not to be bonded, it is not necessary to position chips that are known to be defective in advance at the pickup position as with good chips, so reduce the number of positioning operations. And reduce the man-hours required for bonding. It has become possible.

Further, since the step of recognizing the defective chip is carried out by using the image which is picked up at the same time as the image recognition processing step accompanying the precise positioning of the chip to be bonded, it is carried out without increasing the step of moving the mechanism. Makes it possible.

As described above, the pickup reversing tool 8
Chip 4 picked up from θ table 3 by
After the position is recognized by the transfer recognition camera 15, the position is transferred to the bonding tool 17 based on the recognized position.

After the position of the chip 4 transferred to the bonding tool 17 is recognized by the component recognition camera 24, the chip 4 is positioned and bonded at a predetermined position of the substrate 25 based on the recognition of the substrate recognition camera 26.

When bonding the chip 4 to the substrate 25, the bonding tool 17 descends at a high speed to the search start height, and thereafter descends at a constant speed to bond the chip 4 to the substrate 2.
Bond to 5.

The substrate 25 placed on the bonding stage 27 shown in FIG. 1 may be deformed due to the influence of heat or the like. If the substrate 25 is deformed, the search start height is changed from a high speed descent to a constant speed descent. However, since it varies depending on the bonding position of the chip 4, the search start height may become unnecessarily high in a portion where the deformation amount of the substrate 25 is small, and the tact time of bonding may become long.

As shown in FIGS. 17A and 17B, the search start height at the first bonding is s ₁ ,
Assuming that the height of the bonded chip 4 is t ₁ ,
(T ₁ −s ₁ ) is the search height (distance) ΔA of the bonding tool 17.

If the first chip 4 is bonded, the search start height s of the second bonding is started.
_{The position 2} is located above the height t ₁ of the chip 4 which is initially bonded by a preset search height Δl. The search height s ₃ of the third bonding is set to a position above the height t _{2 of the} second bonded chip 4 by a preset search height Δl.

Thus, the search start heights s ₁ , s ₂ ,
Is the height t ₁ of the chip 4 previously bonded,
Bonding is performed with reference to t ₂ , ... And above the heights t ₁ , t ₂ , ... By a preset search height Δl.

As a result, even if the substrate 25 is deformed, the variation in the search height Δl can be reduced. Therefore, when the substrate 25 is deformed as in the conventional case,
The search height becomes extremely large and the tact time becomes long, or the chip 4 is moved to the substrate 25 depending on the bonding position.
It is possible to prevent the impact from coming into contact with the object being not constant.

Note that in FIG. 17A, for convenience of explanation, the base
Since the amount of deformation of the plate 25 is large, the third bond
Start of search at 4th bonding after
S _FourAnd the height t of the tip 4_FourIs the search height Δl
However, the substrate 25 is usually
The actual search height is preset because it is slightly deformed.
It is said that it becomes extremely small with respect to the determined search height Δl.
I don't care.

(Second Embodiment) In the above-described first embodiment, the component recognition camera 24 for picking up the image of the chip 4 adsorbed on the bonding tool 17 and the board recognition camera 26 for picking up the substrate 25 are separately provided. However, as shown in FIG.
As shown in (b), the substrate 25 mounted on the bonding stage 27 as an integrated type, and the bonding tool 17
You may make it image | photograph simultaneously the chip | tip 4 adsorbed on.

In that case, first, as shown in FIG. 18A, the first recognition point of the substrate 25 is captured by the substrate recognition camera 26 and the first recognition of the chip 4 by the component recognition camera 24 is performed.
Simultaneously capture the recognition points of. That is, when the board recognition camera 26 is positioned so that the first recognition point of the board 25 is in the field of view based on the teaching data,
The bonding tool 17 is positioned so that the first recognition point of the chip enters the field of view of the component recognition camera 24.

Next, as shown in FIG. 18B, the acquisition of the second recognition point of the board 25 by the board recognition camera 26 and the acquisition of the second recognition point of the chip 4 by the component recognition camera 24 are simultaneously performed. To do. Also in that case, the board recognition camera 26 and the bonding tool 17 are positioned based on the teaching data.

When the first and second recognition points of the substrate 25 and the chip 4 are recognized, the chip 4 is positioned at a predetermined position of the substrate 25 based on the data, and then the bonding tool 17 is used. Is lowered and bonding is performed.

Thus, the first recognition point of the substrate 25,
The position information with the first recognition point of the chip 4 is taken in at the same time, and the position information with the second recognition point of the substrate 25 and the second recognition point of the chip 4 are taken in at the same time. Then, the chip 4 is bonded to the substrate 25 during bonding.
It is possible to shorten the recognition time required for positioning with respect to.

[0082]

As described above, according to the present invention, when a large number of chips formed on a semiconductor wafer are sequentially taken out and bonded, fine chips can be bonded reliably and quickly.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic structure of a bonding apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of a control system.

FIG. 3A is a plan view of a front end surface of a pickup reversing tool, and FIG. 3B is a side view.

4A is an image when the bonding tool is at a reference position, and FIG. 4B is an image when the bonding tool is exchanged.

FIG. 5 is a flowchart for teaching a chip size and a chip pitch.

FIG. 6 is a flowchart when registering a chip recognition pattern.

FIG. 7 is a flowchart for registering a leading position detection pattern.

8A and 8B are explanatory views when performing θ correction on a semiconductor wafer.

FIG. 9 is an explanatory diagram for obtaining a chip size and a pitch.

FIG. 10 is an explanatory diagram when teaching a chip recognition pattern.

11A and 11B are explanatory views for teaching a pattern for detecting a head position.

FIG. 12 is a flowchart for performing θ correction of a semiconductor wafer and detection of a leading position based on teaching.

FIG. 13 is an explanatory diagram when roughly adjusting θ of the semiconductor wafer.

14A and 14B are explanatory views for precisely adjusting θ of a semiconductor wafer.

FIG. 15 is a flowchart for detecting a chip position and a defective mark.

FIG. 16 is an explanatory diagram for detecting a chip position and a defective mark.

17A and 17B are explanatory views for setting a search start height when a plurality of chips are sequentially bonded.

18 (a) and 18 (b) are explanatory views when a reference position between a substrate and a chip is imaged, showing a second embodiment of the present invention.

[Explanation of symbols]

1 ... Wafer stage 3 ... θ table 4 ... Chip 5 ... Semiconductor wafer 8 ... Pickup inversion tool 9 ... Nozzle 14 ... Wafer recognition camera 15 ... Handover recognition camera 24 ... Parts recognition camera 25 ... Substrate 26 ... Board recognition camera 31 ... Main controller 32 ... Image recognition control unit 33 ... Wafer stage control unit 34 ... Pickup control unit 35 ... Bonding stage controller 36 ... Camera movement control unit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takao Watanabe             33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa             Inside the Toshiba Production Technology Center (72) Inventor Daisuke Kobayashi             33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa             Inside the Toshiba Production Technology Center (72) Inventor Genjiro Shibata             33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa             Inside the Toshiba Production Technology Center (72) Inventor Tetsuya Kubo             33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa             Inside the Toshiba Production Technology Center (72) Inventor Taizo Tomioka             33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa             Inside the Toshiba Production Technology Center F term (reference) 5F044 PP16 PP17

Claims (9)

[Claims] 1. A bonding apparatus for sequentially taking out a large number of chips formed on a semiconductor wafer and bonding them to a substrate, and an image pickup means for picking up an image of a plurality of chips including at least mirror chips of the semiconductor wafer, and the image pickup means. An image processing unit for detecting the position of the leading chip to be bonded to the substrate from the obtained image, and a bonding apparatus. 2. A bonding method for sequentially taking out a large number of chips formed on a semiconductor wafer and bonding them to a substrate, and an imaging step of imaging a plurality of chips of the semiconductor wafer, and a plurality of images obtained from the imaging step. The recognition step of recognizing the chips, the judgment step of judging whether or not the recognized chips have a defective mark, the step of picking up the chip to bond it to the substrate, and the defective mark based on the above judgment step. And a chip feeding step of controlling to leave a semiconductor wafer by skipping certain chips. 3. A bonding apparatus for sequentially taking out a large number of chips formed on a semiconductor wafer and bonding them to a substrate, and an image pickup means for picking up an image of a plurality of chips of the semiconductor wafer, and a plurality of images obtained by the image pickup means. Image processing means that recognizes the positions of the chips and determines whether or not there are defective marks on the recognized chips, a step of picking up the chips to bond them to the substrate, and a defect based on the above determination step. A bonding apparatus, which comprises a chip feeding step of controlling a semiconductor wafer to be skipped by skipping a chip with a mark. 4. A step of rapidly lowering a bonding tool holding a chip to a predetermined position and a step of lowering the bonding tool lowered to a predetermined position at a constant speed to bond the chip to a substrate are repeated. In the bonding method for bonding a plurality of chips to the substrate, the position at which the bonding tool is moved down at a constant speed is set to be a predetermined dimension higher than the previous bonding position. 5. A chip is held on a bonding tool,
In the bonding method of bonding the chip to the substrate with this bonding tool, a step of imaging the end surface of the reference bonding tool holding the chip, teaching the image, and an image of the end surface of the bonding tool bonding the chip. And a step of comparing the image with an image of the end surface of the teaching reference bonding tool, and a step of controlling the coordinates of the bonding tool when the chip is received from the reversing tool based on the comparison of the two images. A bonding method characterized by the above. 6. A chip is held on a bonding tool,
In the bonding apparatus for bonding the chip to the substrate by this bonding tool, an image of the end surface holding the chip of the reference bonding tool is imaged,
When the image is taught and the image pickup means for picking up the end face of the bonding tool for bonding the chip is compared with the two images picked up by this image pickup means, the chip is received from the reversing tool based on the comparison. A bonding apparatus, comprising: a control unit that controls the coordinates of a bonding tool at the time of bonding. 7. A bonding apparatus for bonding a chip provided on a supply table to a substrate by a bonding tool, comprising a pickup reversing tool for picking up and reversing a chip from the supply table and delivering it to the bonding tool. The bonding device, wherein the end surface of the tool holding the chip is coated with a material that does not emit a metallic luster. 8. A bonding method for bonding a chip held by a bonding tool to a substrate, comprising: a first imaging step of simultaneously imaging the first recognition point of the chip and the first recognition point of the substrate; Second of the chip
Based on the coordinates of the recognition points of the chip and the substrate, which are imaged in the first and second imaging steps, and the second imaging step of simultaneously imaging the recognition point and the second recognition point of the substrate. And a step of positioning the chip and bonding it to the substrate. 9. In a bonding apparatus for bonding a chip held by a bonding tool to a substrate, a first recognition point of the chip and a first recognition point of the substrate are simultaneously imaged, and then a second recognition of the chip is performed. Imaging means for simultaneously imaging the recognition point and the second recognition point of the substrate,
A bonding apparatus comprising: a control unit that positions the chip based on the image pickup result of the image pickup unit and bonds the chip to the substrate.