JPH05183022A - Chip automatic selection and transfer apparatus - Google Patents

Abstract

PURPOSE:To provide an apparatus for discriminating good and no good conditions of chips and simultaneously arranging the chips, moreover picking up chips and simultaneously checking again the good and no good conditions of chips by comprising particular a semiconductor wafer loading tray, a chip arranging device, an optical detecting device and a collet. CONSTITUTION:This chip automatic selection and transfer apparatus comprises a semiconductor wafer loading tray 21 for loading diced semiconductor wafer 1 to move in the X-Y directions and a chip arranging device 22 for arranging good chips 1d transferred from the loading tray 21 while these are moved in the X-Y directions. Moreover, at least an optical detecting device 23 is also provided in the upper part of the chips 1d to be transferred in order to discriminate the good or no good condition of the chips 1d by detecting the marks applied on the chips 1d. In addition, at least three sets of collet 24 are provided in such a manner as being arranged with the equal interval on the same circumference around the rotating axis and moved in the axial direction of the rotating axis to receive the good chips 1d from the loading tray 21 and transfer the chips 1d to the chip arranging device 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip automatic sorting and conveying apparatus, and more particularly, to determine the quality of a conveyed chip on a semiconductor wafer loading table by an optical detecting device and at the same time align the chips in a chip aligning device. At the same time as pressing and picking up chips from the semiconductor wafer loading table, the quality of the chips conveyed to the chip aligning apparatus is checked again by an optical detection device. The present invention relates to an automatic chip sorting / transporting device having an epoch-making performance that can be transported to other devices.

[0002]

2. Description of the Related Art A semiconductor wafer 1 is a general term for thin disk-shaped semiconductors with reference to FIGS. 4 and 5, and is usually cut into a disk shape from a single crystal base material refined into a cylinder shape. One surface 1a is mirror-polished, and various semiconductor elements are formed on the surface by an etching method or the like.

The semiconductor wafer 1 has, for example, a size of 10 to 400 mmφ and a thickness of 200 μm to 10 m.
m is a thin disk shape, and a so-called orientation flat 1b is formed by linearly grinding the outer peripheral portion, that is, a part of the end face in order to easily match the orientation in the circumferential direction.

A large number of semiconductor elements manufactured on the semiconductor wafer 1 by an etching method or the like are inspected one by one for electrical characteristics, and if the predetermined characteristics cannot be obtained, a mark 1c is attached as a defective element (probing process). ).

A semiconductor wafer 1 having a mark 1c attached to a defective element is attached to a tape 2 and cut into chips (semiconductor elements) 1d having a side of 0.5 mm to 20 mm by a cutting device (not shown). To be separated.

Then, non-defective non-marked chips 1d are selected from a large number of separated chips 1d, picked up and sorted into trays, or conveyed to a bonding process.

In a conventional chip 1d conveying apparatus, in FIG. 6, a pulse motor or a servomotor 6 rotates a male screw 5 which is screwed with a nut 4 to which a collet 3 holding the chip 1d is fixed, in the direction of arrow A or B. Then, the collet 3 is conveyed in the direction of arrow C or D.

However, although the feed screw type transfer device has little vibration and is excellent in stability, it is difficult to operate at high speed. For example, one semiconductor wafer 1
However, there is a drawback in that it takes too much time to process the semiconductor wafer 1 on which approximately 8000 chips 1d are formed and it is not economical.

As another carrying device, as shown in FIG. 7, a wire 1 having a collet 9 fixed to a pair of pulleys 8 is used.
It is known that 0 is wound around and the pulley 8 is rotated in the arrow E or F direction by the motor 11 to convey the collet 9 in the arrow G or H direction.

Although the wire-type transfer device has been greatly improved in high speed as compared with the feed screw-type transfer device, vibration at the time of stoppage due to elasticity of the wire 10 and elongation over time. However, there is a drawback that it is difficult to secure the position accuracy due to the change of.

As another carrying device, as shown in FIG. 8, two collets 14 are fixed to a rotating shaft 13 of a motor 12 and the motor 12 is intermittently rotated in the direction of arrow I every 180 ° to rotate the rotating shaft. The one in which the chip 1d is transported to 13 symmetrical positions has been adopted.

The transfer device has been greatly improved in terms of high speed and positional stability, but since the two collets 14 are arranged symmetrically with respect to the rotary shaft 13, the transfer chip 1d has a true position. While the mark 1c attached to the chip 1d is detected by the optical detection device arranged above to determine the quality of the chip 1d, the collet 14 is rotated so as not to interfere with the quality determination. It was necessary to wait at an intermediate position, and there was still room for improvement in high speed.

Further, in any of the above-mentioned transfer devices, the vertical movement of the collet 4 is controlled by the cylindrical cam with which the collet 4 engages, so that the vertical position of the collet 4 at the time of picking up the chip 1d and pressing. However, there are drawbacks such that the fine adjustment is difficult and the chip 1d cannot be delivered reliably, or the collet 4 is strongly pressed against the chip 1d to damage the chip.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the above-mentioned drawbacks of the prior art. The object of the present invention is to provide at least 120 on the same circumference about the rotation axis. By arranging three sets of collets at intervals of 60 °, and intermittently rotating the collets by 60 ° around the rotation axis to convey the chips, the quality of the conveyed chips is determined by an optical detection device and at the same time the chips are aligned. It is to align and press the chip on the device, and to pick up the chip from the semiconductor wafer loading table and at the same time enable the optical detector to confirm again whether the chip transferred to the chip alignment device is good or bad. Eliminating the idle period of the automatic chip sorting and conveying device to improve the moving efficiency and enable the chip to be conveyed at a much higher speed than before. Is Rukoto.

Another object of the present invention is to make it possible to surely prevent defective elements from being conveyed by determining whether the chips are defective or not twice by the above-mentioned structure before and after the conveyance.

Still another object is to move the collet up and down by using a servo motor capable of arbitrarily setting the stop position of the collet in the up and down direction. It is to be able to transfer chips from the wafer loading table to the chip aligning device, and to facilitate the adjustment of the collet stop position to ensure the delivery of chips with the spacing between the chip and the collet at the time of delivery as the optimum interval. It is possible to transport the chips without damaging them.

[0017]

SUMMARY OF THE INVENTION In summary, the present invention (claim 1) is to load semiconductor wafers on which a plurality of chips are diced and to move in the X direction and in the Y direction orthogonal to the X direction. A table, a chip alignment device for aligning a good chip conveyed from the semiconductor wafer loading table to a predetermined position while moving in the X direction and the Y direction, and a mark attached to the chip to detect the mark of the chip. An optical detection device disposed at least above the conveyed chip for determining pass / fail, and arranged at equal intervals on the same circumference centered on the rotation axis and configured to be rotatable around the rotation axis. And at least three sets for moving the chips in the axial direction of the rotary shaft by a driving device to transfer the non-defective chips from the semiconductor wafer loading table and transporting the chips to the chip aligning device. It is characterized in that a let.

Further, according to the present invention (claim 2), a semiconductor wafer loading table for loading a semiconductor wafer diced on a plurality of chips and moving it in the X direction and the Y direction orthogonal to the X direction, and the semiconductor are provided. A chip aligning device that aligns a good chip conveyed from the wafer loading table in a predetermined position while moving in the X direction and the Y direction, and a mark attached to the chip can be detected to determine whether the chip is good or bad. As described above, at least the optical detection device arranged above the conveyed chip and the optical detection device on the same circumference centered on the rotation axis
The chips are arranged at intervals of 20 °, rotate intermittently by 60 ° about the rotation axis, and are moved in the axial direction of the rotation axis by a driving device to transfer non-defective chips from the semiconductor wafer loading table to the chip alignment device. And three sets of collets for carrying the chips.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the drawings. 1 to 5, an automatic chip sorting and conveying apparatus 20 according to the present invention includes a semiconductor wafer loading table 21 and
A chip alignment device 22, an optical detection device 23, and a collet 24 are provided.

The semiconductor wafer loading table 21 loads the semiconductor wafers 1 diced into a plurality of chips 1d with reference to FIG. 1, moves in the arrow J or K direction and the arrow L or M direction, and then carries them. This is a well-known XY moving device for sequentially transporting the chips 1d scheduled to be carried out to a predetermined pickup position by the collet 24.

The tape 2 is mounted on the semiconductor wafer loading table 21.
The semiconductor wafer 1 affixed to is positioned and stacked by the orientation flat 1b.

Below the predetermined pick-up position of the collet 24, there is provided a chip peeling device (not shown) having a needle attached upward, and in cooperation with the collet 24, the needle is pushed upward to push the chip upward. 1d is peeled off from the tape 2 and delivered to the collet 24.

The chip aligning device 22 is for aligning the good chips 1d conveyed from the semiconductor wafer loading table 21 by the collet 24, and is a known XY.
This is a moving device, and a tray 25 for accommodating the chips 1d is loaded on the table 22a.

Each time the chip 1d is conveyed by the collet 24, the tray 25 is moved in the direction of arrow N or O and the direction of arrow P or Q so that the chip 1d is aligned and stored (pressed) in the tray 25. Is becoming

The optical detection device 23 is for determining the quality of the chip 1d, and is configured as, for example, a microscope device or an image processing device linked with a CCD camera or the like, and is to be transported next. The chip 1d is focused and disposed above a predetermined pickup position of the semiconductor wafer loading table 21, and the shape of the chip 1d and the defective mark 1c provided in the electrical inspection process are detected to detect the chip 1d. It is designed to judge pass / fail.

The optical detecting device 23 is also disposed above the pressing position of the chip aligning device 22, and the chips 1d that are aligned and stored (pressed) in the tray 25 are checked again to find defective chips 1d. It is designed to prevent accidental transportation.

The collet 24 is for transporting the chips 1d from the semiconductor wafer loading table 21 to the tray 25 of the chip aligning device 22, and also referring to FIG.
A rotation shaft 29 is rotatably and pivotally attached to a support base 28 fixed to 6.

A cylindrical cam body 30 is provided below the support base 28.
Is provided, and the guide pin 31 fixed to the cylindrical cam body 30 is slidably fitted to the guide block 28a of the support base 28 so that the cylindrical cam body 30 can be moved up and down in the arrow R or S direction. Hold on.

An AC servomotor 32 that can be stopped at an arbitrary position, which is an example of a drive device, is fixed to the support base 28, and is screwed to a male screw 34 fixed to a rotary shaft 33 of the AC servomotor 32. The feed block 35 is fixed to the cylindrical cam body 30, and is configured to move the cylindrical cam body 30 in the arrow R or S direction by rotating the AC servomotor 32.

The stop position of the cylindrical cam body 30 due to the rotation of the AC servomotor 32 is such that the collet 24 contacts the chip 1d loaded on the semiconductor wafer loading table 21 and the chip 1d is peeled off from the tape 2. It is set to three positions, that is, a retracting position for picking up and a pressing position for pressing the chip 1d conveyed to the chip aligning device 22 to the chip aligning device 22, and each stop position can be adjusted in units of 10 μm. ..

A rotary shaft (not shown) of a drive device 36 that can be stopped at an arbitrary position such as an AC servo motor or a step motor is connected to the upper end of the rotary shaft 29, and the collet 24 is stopped every 60 °. It is set to rotate intermittently. Three sets of stays 38 are fixed to the lower end 29a at 120 ° intervals.

A movable block 40, to which the collet 24 is fixed by a screw 39, is fitted in a guide groove 38a formed on the outer peripheral portion of the stay 38, and the movable block 40 is guided to slide in the directions T and U. It is freely movable.

At the upper end 40a of the movable block 40, a vertical lift amount formed on the outer periphery of the cylindrical cam body 30 is approximately 2.
A guide roller 41 slidably fitted in the 0 mm cam groove 30a is mounted by a screw 42.

The three sets of collets 24 are movable blocks 40.
, And are arranged at 120 ° intervals on the same circumference with the axis of the rotating shaft 29 as the center.

When the rotary shaft 29 is driven by the driving device 36, the three sets of stays 38 also rotate, and the movable block 40 fitted in the guide groove 38a rotates around the cylindrical cam body 30 and also in the cam groove 30a. Guided by arrows T and U
It is designed to move up and down in a certain direction.

That is, the collet 24 located on the semiconductor wafer loading table 21 is guided by the cam groove 30a as it rotates in the direction of the chip aligning device 22 (direction of arrow V), and its lift amount (20 mm). It gradually rises (in the direction of arrow T), and the lift amount of the cam groove 30a is set to be substantially the same as the height difference between the conductive wafer loading table 21 and the chip alignment device 22. ..

The collet 24 is connected to a vacuum device (not shown) by a tube 43. The vacuum device is controlled to adsorb the chip 1d by the collet 24 to pick it up from the semiconductor wafer loading table 21, and the chip aligning device 22. It is designed to be pressed.

The present invention is configured as described above,
The operation will be described below. Referring also to FIG. 3, the semiconductor wafer loading table 21 is moved in the arrow J or K direction and the arrow L or M direction to position the chip 1d to be transferred next below the optical detection device 23.

Next, the optical detector 23 checks whether the shape of the chip 1d to be conveyed next is a normal shape or whether the defective mark 1c is attached,
It is confirmed that the chip 1d is a good product.

At this time, since the positional relationship between the three sets of collets 24 is as shown in FIG. 3, the driving device 36 rotates the three sets of collets 24 in the direction of arrow V by 60 ° via the rotary shaft 29. , One of the collets 24 into the cam groove 30
While descending along a, it is positioned slightly above the chip 1d to be conveyed next, which has been checked to be a good product.

The tip of the collet 24 positioned slightly above the tip 1d to be next conveyed with the cylindrical cam body 30 together with the feed block 35 which is driven to rotate the male screw 34 by the AC servomotor 32 and is screwed to the male screw 34 is attached to the tip 1d. The tip 1d is lowered to the contact position in the direction of arrow U, and the chip 1d is adsorbed to the collet 24 by a vacuum device (not shown).

The AC servo motor 32 is again rotated in the opposite direction to raise the collet 24 in the direction of the arrow T, and in conjunction with this, the needle of the chip peeling device (not shown) is pushed up through the tape 2 to push the chip. 1d tape 2
Peel it off and hand it over to collet 24.

In the pickup process, the collet 2
4 and the upward movement of the needle of the chip peeling device are controlled in perfect synchronization by electronic control, unlike the conventional cam control, so that the collet 24 is strongly pressed against the chip 1d to damage the chip 1d. There is no such thing.

From the semiconductor wafer loading table 21 to the chip 1
While picking up d, none of the collets 24 of the three sets of collets 24 is located above the press position of the chip aligning device 22, and the chips 1d already conveyed and aligned on the tray 25 are good products. Whether or not it is checked again by the optical detection device 23.

When the driving device 36 is driven again and the three sets of collets 24 are further rotated in the direction of arrow V by 60 °, the collets 24 are guided by the cam groove 30a and ascended by about 20 mm (direction of arrow T). The positional relationship shown in FIG. That is, the collet 24 is not located below the optical detection device 23 of the semiconductor wafer loading table 21, but the collet 24 is located at the press position of the chip alignment device 22.

Here, the AC servo motor 32 is rotated to lower the collet 24 in the direction of the arrow U, and the action of the vacuum device of the collet 24 at the press position is stopped to stop the chip 1
The d is detached from the collet 24, aligned in the empty tray 25, and stored (pressed).

At the same time, the semiconductor wafer loading table 21 is moved in the direction of arrow J or K and the direction of arrow L or M to position the chip 1d to be transferred next below the optical detection device 23, and the The detection device 23 checks whether or not the chip 1d to be conveyed next is a non-defective product. If the shape of the chip 1d is not the predetermined shape or the defective mark 1c is attached, the semiconductor wafer loading table 21 is again moved to the arrow J or K direction and the arrow L.
Alternatively, the same operation is repeated until the non-defective chip 1d is detected by moving in the M direction, and the non-defective chip 1d is positioned at the pickup position.

After storing (pressing) the chip 1d in the tray 25, the AC servo motor 32 is rotated again to raise the collet 24, and the chip aligning device 22 is moved in the arrow N or O direction and the arrow P or Q direction. Then, the empty tray 25 is positioned below the pressing position to prepare for the next conveyance of the chip 1d.

The above operation of intermittently rotating the collet 24 every 60 ° is repeated, and the chips 1d are transferred one by one from the semiconductor wafer loading table 21 to the tray 25 of the chip aligner 22 at a high speed in the arrow W direction and stored. To do.

Next, the relationship between the number of collets 24 and the time required to convey the chips 1d will be described with reference to Table 1.

[0051]

[Table 1]

In Table 1, the image processing time required for determining the quality of the chip 1d by the optical detecting device 23 is 0.2.
The pickup time required for picking up the chip 1d from the semiconductor wafer loading table 21 is 0.3 seconds, and the pressing time required for storing the chip 1d in the chip alignment device 22 is 0.2 seconds, which is constant regardless of the number of collets 24.

One collet 24 and one chip 1
In the case of Example 1 of the conventional method which requires rotation of 180 ° to convey d, by intermittently rotating the collet 24 by 90 °, it is possible to determine whether the tip 1d is good or bad when the collet 24 is at the intermediate position rotated by 90 °. Since the determination is made, no special image processing time is required. Therefore, one chip 1d
As for the time required for the conveyance, the rotation time required for rotating the collet 24 by 180 ° is added to 0.9 seconds, and the total time is 1.4 seconds.

In the case of Example 2 of the conventional method in which the number of collets 24 is two and one chip 1d needs to be rotated by 90 ° to convey one chip 1d, the time required for rotating the collet 24 by 90 ° is 0. 45 seconds is added to each time mentioned above,
The total time is 0.95 seconds.

In the embodiment of the present invention of Example 3 in which the number of collets 24 is three, the rotation time required for rotating the collet 24 by 60 ° is 0.3 seconds, and the total time is 0.8 seconds.

Further, in the case of Examples 4 and 5 in which four and five collets 24 are provided, the rotation angles are 45 ° and 36 °, respectively, and the total time is 0.725 seconds and 0.68 seconds. Become.

As shown in Table 1, the larger the number of collets 24, the shorter the transportation time per chip, but
Since the mechanism becomes more complicated as the number of collets 24 increases, the number of collets 24 is about three, which is the most efficient configuration example.

In the above-mentioned embodiment, the chip aligning device is described as storing the chips in the tray, but the chip aligning device is not limited to storing the chips in the tray. It may be any device in the next step such as a bonding device.

[0059]

As described above, according to the present invention, three sets of collets are arranged at intervals of at least 120 ° on the same circumference centered on the rotation axis, and the collets are intermittently rotated by 60 ° about the rotation axis. Since the chips are transported by the optical detector, the optical detector is used to determine the quality of the transported chips, and at the same time the chips are aligned and pressed in the chip aligner, and at the same time the chips are picked up from the semiconductor wafer loading table. There is an effect that the quality of the chips conveyed to the aligning device can be confirmed again by the optical detection device, and as a result, the chip automatic sorting and conveying device eliminates the idle period to improve the moving efficiency, and the chips are much faster than the conventional one. The effect of being able to carry

Further, according to the above structure, it is possible to surely prevent the defective element from being conveyed by determining the quality of the chip twice before and after the conveyance.

Further, since the collet is moved in the vertical direction by using the servo motor capable of arbitrarily setting the stop position of the collet in the vertical direction, the semiconductor wafers having different heights can be moved by one servo motor. There is an effect that the chips can be conveyed from the loading table to the chip aligning device, and as a result, the adjustment of the collet stop position can be facilitated and the chip can be reliably delivered with the interval between the chip and the collet at the time of delivery being the optimum interval. At the same time, there is an effect that the chips can be transported without being damaged.

[Brief description of drawings]

1 to 5 relate to an embodiment of the present invention, and FIG. 1 is an overall perspective view of an automatic chip sorting and conveying apparatus.

FIG. 2 is a front view of essential parts of an automatic chip sorting and conveying device.

FIG. 3 is a plan view showing a chip transport state by a collet.

FIG. 4 is a front view showing a diced semiconductor wafer.

FIG. 5 is a plan view of a semiconductor wafer having a mark of a defective element.

6 to 8 relate to a conventional example, and FIG. 6 is a front view of a feed screw type transport device.

FIG. 7 is a front view of a wire-type transfer device.

FIG. 8 is a front view of a rotary transfer device having two collets.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 semiconductor wafer 1c mark 1d chip 20 chip automatic sorting and conveying device 21 semiconductor wafer loading table 22 chip aligning device 23 optical detecting device 24 collet 29 rotating shaft 36 servo motor as an example of a driving device

[Table 1]

Claims (3)

[Claims] 1. A semiconductor wafer, which is diced on a plurality of chips, is loaded and an X direction and a Y direction orthogonal to the X direction are stacked.
The semiconductor wafer loading platform that moves in the X-direction and the non-defective chips transferred from the semiconductor wafer loading platform in the X direction and the Y direction.
A chip aligning device for aligning at a predetermined position while moving in a direction, and an optical detector arranged at least above the conveyed chip for detecting a mark attached to the chip to determine whether the chip is good or bad. The device and the semiconductor wafer loading table are arranged at equal intervals on the same circumference centered on the rotation axis and are configured to be rotatable around the rotation axis, and are moved in the axial direction of the rotation axis by a driving device. An automatic chip sorting and conveying device, comprising: at least three sets of collets for delivering the non-defective chips to the chip aligning device. 2. A semiconductor wafer, which is diced on a plurality of chips, is loaded and the Y direction is orthogonal to the X direction.
The semiconductor wafer loading platform that moves in the X-direction and the non-defective chips transferred from the semiconductor wafer loading platform in the X direction and the Y direction.
A chip aligning device for aligning at a predetermined position while moving in a direction, and a chip aligning device arranged at least above the conveyed chip so as to detect the mark attached to the chip and determine the quality of the chip. The optical detection device and the semiconductor are arranged at 120 ° intervals on the same circumference centered on the rotation axis, rotate intermittently by 60 ° about the rotation axis, and move in the axial direction of the rotation axis by a driving device to move the semiconductor. An automatic chip sorting / transporting device, comprising: three sets of collets for delivering the non-defective chips from the wafer loading table and transporting the chips to the chip aligning device. 3. The chip automatic sorting and conveying apparatus according to claim 1, wherein the driving device is a servo motor capable of setting a stop position at an arbitrary position.