JP2001217302A - Pellet pickup apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a pellet pickup apparatus to be improved in throughput and reduced in size without resetting a suction nozzle nor requiring a suction nozzle rotating mechanism by making the moving range of a wafer stage smaller. SOLUTION: A pellet pickup apparatus is equipped with a wafer stage 20 on which a wafer is placed, a pushing unit 10 which picks up pellets obtained by dicing a wafer, a pushing unit moving means 12 which moves the pushing unit 10 to a prescribed position, a wafer stage moving means 32 which successively moves the pellets on the wafer stage 20 to the pickup target position of the pushing unit 10, and a pushing unit driving unit which drives the pushing unit 10 to pick up the pellets which are successively moved to the pickup target position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus and a method for picking up pellets, and more particularly, to an apparatus and a method for picking up a pellet which can reduce a moving range of a wafer holder.

[0002]

2. Description of the Related Art Conventionally, in order to prevent the movement range of a wafer stage from being increased due to an increase in the diameter of a wafer, a wafer is required
One or four regions are equally divided, and a wafer stage on which a wafer is mounted is appropriately rotated to take out semiconductor pellets (hereinafter, referred to as “pellets”) for each of the divided regions.

FIG. 5 shows a wafer divided equally into four regions.
FIG. 3 is a diagram for explaining a conventional method of picking up a pellet. As shown in FIG. 5, first, the wafer stage 20 is arranged so that the center (position A) of the wafer 2 and the position to be pushed up by the push-up unit match, and thereafter, the wafer stage 20 is moved in the X direction by -D / 2. Move -D / 2 in the Y direction to pick up the pellet in the first area (D is the diameter of the wafer).

Next, after rotating the wafer stage 20 by 90 degrees to move the pellets in the second area to the first quadrant, the wafer stage 20 is moved in the X direction in the same manner as when the pellets in the first area are picked up. To -D / 2 and -D / 2 in the Y direction to pick up the pellets in the second region.

Similarly, the wafer stage 20 is rotated by 90 degrees to pick up the pellets in the third and fourth regions. The movement range of the wafer stage 20 at this time is indicated by a wafer stage movement range 50.

When the pellets are taken out of the wafer stage 20, the pellets are pushed up from below the wafer sheet to which the pellets are adhered using a push-up needle of a push-up unit, and the pellets are separated from the wafer sheet. It operates in synchronization with this push-up needle,
The pellets are sucked from above using the suction nozzles of the transfer unit and the like.

FIG. 6A shows the tip of the suction nozzle.
And a pyramid collet 151 as shown in FIG. The pyramid collet 151 has a suction hole 153,
The surface that adsorbs the pellet 155 is a concave inclined surface 157. Then, only the upper side of the pellet contacts this inclined surface 157. Thereby, the pyramid collet 151
Can contact and hold the pellet 155 without contacting the surface of the pellet 155.

[0008] The pyramid collet 151 is a pellet 1
A shape and size corresponding to 55 are used. That is, as shown in FIG. 6B, when the pellet 155 is rectangular, the pyramid collet 151 also has a rectangular shape.

[0009]

However, the wafer 2 is equally divided into four regions, and the wafer stage 20 is
The above-described conventional method of picking up pellets by rotating each time has the following problems.

That is, when a vertically long pyramid collet 151 is used to adsorb the rectangular pellet 155,
When the wafer stage 20 is rotated by 90 degrees, the direction of the rectangular pellet 155 is also rotated by 90 degrees. For this reason,
As shown in FIGS. 7A and 7B, the rectangular pellet 1
55 protrudes from the pyramid collet 151, and a sufficient suction force cannot be obtained, which hinders the removal of the pellet 155.

In order to avoid this, every time the rotary stage is rotated by 90 degrees, the worker manually rotates the direction of the suction nozzle by 90 degrees, or a suction mechanism is provided to the suction nozzle to automatically perform suction. It is necessary to change the direction of the nozzle.

However, if the direction of the suction nozzle is manually changed, it takes time and productivity is reduced. In addition, since the suction nozzle reciprocates at a high speed between the pellet pick-up position on the wafer stage and the position correction table, if a rotating mechanism is provided to increase the weight, high-speed movement will be hindered. It is not preferred.

Therefore, the present invention has been made to solve the above-mentioned problems, and does not change the direction of the pellets, that is, does not require a suction nozzle rotating mechanism or the like, and the pellets can be divided for each divided area. It is an object of the present invention to provide a device capable of taking out quickly.

[0014]

In order to achieve the above object, according to the first aspect of the present invention, a group of pellets obtained by dicing a wafer is divided into a plurality of regions, and the pellets are divided for each of the divided regions. In a pellet pickup device for taking out the wafer, a wafer stage on which the wafer is mounted, a push-up unit for pushing up each pellet on the wafer stage, and a predetermined position corresponding to each divided area of the wafer A push-up unit moving means for moving the respective pellets on the wafer stage to the push-up unit by the push-up unit positioned at the predetermined position corresponding to the area for each area. A wafer stage moving means for moving the wafer stage; and each of the wafers sequentially moved to the push-up target position. Characterized by comprising a push-up unit driving means for driving the push-up unit to pick up the Tsu bets.

Thus, each pellet obtained by dicing the wafer is divided into a plurality of regions, and when the pellets are taken out for each of the divided regions, the push-up unit is moved to an appropriate position according to each region. This makes it possible to reduce the size of the pellet pickup device and increase the speed of the pellet pickup operation.

Further, the invention of claim 2 is characterized in that it comprises a wafer stage rotating means for rotating the wafer stage.

Thus, for example, when each pellet is divided into four regions and picked up in each region, the size of the pellet pickup device and the speed of the pellet pickup operation are increased as in the first aspect of the present invention. be able to.

A third aspect of the present invention is a pellet pick-up method in which a group of pellets obtained by dicing a wafer is divided into a plurality of regions, and a pellet is taken out by using a push-up unit for each of the divided regions. The direction and amount of movement of the push-up unit when switching from one region to another region in a plurality of regions into which the pellets are to be taken out are divided into one region and the other region virtually. The direction and amount of movement of the other region with respect to the one region when a rectangle circumscribing a virtual composite region of the one region and the other region formed by relative movement has a minimum area. It is characterized in that it is determined based on this.

According to such a method, it is possible to determine the moving direction and the moving amount of the push-up unit which are optimal for downsizing the pellet pickup device.

Further, according to the invention of claim 4, each pellet obtained by dicing the wafer is divided into four regions by an X axis and a Y axis orthogonal to each other at the center of the wafer, and each of the divided regions is divided into four regions. A method of picking up each of the pellets using a push-up unit, wherein the push-up unit is positioned at the center of the wafer, and the wafer is moved to push up each pellet in a first area. The pellets in the first area are sequentially picked up by the push-up unit, and then the push-up unit is moved from the center of the wafer to the X-axis or the Y-axis and the wafer. Moving to a point of intersection with the outer periphery and not in contact with the first area,
The wafer is moved in substantially the same manner as when the pellets in the first area are picked up, whereby each pellet present in the second area is sequentially moved to a position to be pushed up by the push-up unit, The pellets in the second area are sequentially picked up by the push-up unit, and then the wafer is rotated by 180 degrees, so that the second
The pellets in the third area are sequentially picked up in the same manner as in the case where the pellets in the area are picked up.
As in the case where the pellets in the region (4) are picked up, the pellets in the fourth region are sequentially picked up.

According to this method, the pellet can be picked up from any region without changing the longitudinal direction of the pellet, that is, without changing the direction of the suction nozzle.

In any case where the pellet is taken out from any area, the moving range of the wafer is D / 2 at the maximum in both the X and Y directions (D is the diameter of the wafer).

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram for explaining the outline of the configuration of the pellet pickup device of the present invention.

As shown in FIG. 1, the pellet pickup device of the present invention comprises a push-up unit 10 for pushing up a semiconductor pellet, a push-up unit moving means 12 for moving the push-up unit 10 in a horizontal direction, and a push-up unit 10.
Unit driving means 14 for driving the wafer, a wafer stage 20 on which a wafer is mounted, and a wafer stage 20
, A wafer stage rotating means 32 for moving the wafer stage 20 in the horizontal direction, and a control unit 40 for controlling each means such as the push-up unit moving means 12.

The push-up unit 10 has a push-up rod (not shown) for pushing up the pellet on the wafer sheet from below. The pellet pushed up by the push-up bar is sucked (picked up) by a suction nozzle (not shown) of a pellet transfer or the like that operates in synchronization with the push-up bar.

Next, a pellet pickup method according to the first embodiment of the present invention will be described with reference to FIG.
In the first embodiment, the wafer is equally divided into four regions, and pickup is performed for each region.

As shown in FIG. 2A, when the center of the wafer 2 coincides with the intersection of the X axis and the Y axis, the first quadrant on the upper right is the first area, and the second quadrant on the upper left is the third area. Area, lower left third
The quadrant is defined as a fourth area, and the lower right fourth quadrant is defined as a second area. Note that, as shown in FIG.
After the rotation, the fourth region exists in the first quadrant, the second region exists in the second quadrant, the first region exists in the third quadrant, and the third region exists in the fourth quadrant.

As will be described later, the order of pickup in the present embodiment is different from the order of pickup in the conventional method described with reference to FIG. 5, so that the positional relationship between the third region and the fourth region in FIG. Is different from that in FIG.

First, a case where a pellet is taken out from the first region will be described with reference to FIG. The vertical direction (Y direction) of the pellet is the longitudinal direction.

As shown in FIG. 2A, the wafer stage 20 is positioned such that the center of the wafer 2 placed on the wafer stage 20 is located at the intersection (position A: reference position) between the X axis and the Y axis.
And the push-up unit is also located at the position A.

If the right direction is + (plus) on the X axis and the upward direction is + (plus) on the Y axis, the wafer stage 20 is required to take out (pick up) all the pellets in the first area. At the maximum -D / 2 in the X direction and -D / 2 in the Y direction (D is the diameter of the wafer 2). The maximum range in which the wafer stage 20 moves is indicated by a wafer stage moving range 50.

Further, while all the pellets in the first area are taken out, the push-up unit does not move in the horizontal direction (the horizontal direction with respect to the plane of FIG. 2).

Next, a case where the pellet is taken out from the second region will be described with reference to FIG.

As shown in FIG. 2B, the push-up unit is moved to the lower end position of the wafer 2 (position B). That is, it is moved by -D / 2 in the Y direction. In a case where all the pellets in the second region are taken out, the wafer stage 20 is moved up to −D / 2 in the X direction and −D / Move two. The maximum range in which the wafer stage 20 moves is indicated by a wafer stage moving range 52.

The moving range 52 is slightly different from the moving range 50. That is, the moving range 50 and the moving range 52 have the same shape but different directions. The reason is that the first region is a sector of a right upper arc centered on the lower left, and the second region is a sector of a lower right arc centered on the upper left.

Although the push-up unit is moved before the start of the pickup in the second area, the orientation of the pellet does not change because the wafer stage 20 is not rotated. Therefore,
There is no need to rotate the suction nozzle.

Next, a case where the pellet is taken out from the third region will be described with reference to FIG.

As shown in FIG. 2C, the third region is moved from the second quadrant to the fourth quadrant by rotating the wafer stage 20 by 180 degrees. The push-up unit is not moved from the lower end (position B) of the wafer 2.

In order to take out all the pellets in the third region, as in the case of taking out the pellets in the second region,
The wafer stage 20 is moved at most by -D / 2 in the X direction and -D / 2 in the Y direction. The maximum range in which the wafer stage 20 moves is the wafer stage moving range 52, as in the case where the pellets in the second area are taken out.

Although the wafer stage 20 is rotated by 180 degrees, the pellet can be sucked without rotating the suction nozzle because the longitudinal direction of the pellet remains in the Y direction.

Finally, a case where the pellet is taken out from the fourth region will be described with reference to FIG.

When the third area has been moved from the second quadrant to the fourth quadrant, the fourth area has been moved to the first quadrant.

Therefore, in order to remove all the pellets in the fourth area, the push-up unit is moved to the center of the wafer 2 (position A) without rotating the wafer stage 20, that is, + D / 2 in the Y direction. Move it and then
As in the case where the pellets in the first area are taken out, the wafer stage 20 is moved up to -D / 2 in the X direction and -D in the Y direction.
/ 2 moves. The maximum range in which the wafer stage 20 moves is the wafer stage movement range 50, as in the case where the pellets in the first area are taken out.

Since the longitudinal direction of the pellet remains in the Y direction, the pellet can be sucked without rotating the suction nozzle.

As described above, the wafer stage 20 can be moved up to X
-D / 2 in the direction and -D / 2 in the Y direction. Therefore, the moving range of the wafer stage is D / 2, Y in the X direction.
D / 2 in the direction, the wafer 2 is divided into four regions, and the wafer 2 is rotated by 90 degrees and picked up,
The moving range of wafer stage 20 can be reduced.

When the pellets are taken out from any of the first to fourth regions, since the longitudinal direction of the pellets remains in the Y direction, the pyramid collet 151 shown in FIG.
When using the suction nozzle (pyramid collet 1)
The pellet can be adsorbed without rotating 51).

In this embodiment, the push-up unit is moved from the center of the wafer (position A) to the lower end of the wafer (position B). Such a method of determining the moving direction and the moving amount will be described with reference to FIG.

FIG. 3A is a diagram schematically showing two right-half regions (sectors T1 and T2) when the wafer is divided into four regions. Here, the moving direction and the moving amount of the push-up unit when switching the take-out area of the pellet from one area T1 to another area T2 are one area T.
When the area R1 and the other area T2 are virtually moved relative to each other, the area of the rectangle R circumscribing the synthesis area (virtual synthesis area) formed by the two areas T1 and T2 is minimum, that is, FIG.
The region T with respect to the region T2 when the state shown in FIG.
1 is determined based on the moving direction and the moving amount. Specifically, in FIG. 2, the moving direction and the moving amount of the push-up unit when switching the pellet take-out region from the first region to the second region are determined by the distance between the first region and the second region in the Y direction. Since the area of the circumscribed quadrangle of the combined area formed by the first area and the second area when moving by -D / 2 becomes the minimum, the area becomes -D / 2 in the Y direction.

Next, a pickup method according to a second embodiment of the present invention will be described. In the second embodiment, the wafer is equally divided into two regions, and pickup is performed for each region.

First, the case of taking out a pellet from the first region will be described with reference to FIG. The vertical direction (Y direction) of the pellet is the longitudinal direction.

As shown in FIG. 4A, the wafer 2 placed on a wafer sheet (not shown) on the wafer stage 20
The wafer stage 20 is arranged so that the center of the wafer 2 is located at the intersection of the X axis and the Y axis (position A: reference position), and the push-up unit is positioned at the center of the wafer 2.

In order to take out (pick up) all the pellets from the upper half area, the wafer stage 20
At the maximum, ± D / 2 in the X direction and −D / 2 in the Y direction. The maximum range in which the wafer stage 20 moves is indicated by a wafer stage moving range 54.

Further, while all the pellets are taken out from the upper half area, the push-up unit does not move in the horizontal direction (horizontal direction with respect to the plane of FIG. 4).

Next, a case where the pellets are taken out from the lower half region will be described with reference to FIG.

First, the push-up unit is moved to the lower end (position B) of the wafer 2. That is, it is moved by -D / 2 in the Y direction. In order to take out all the pellets in the lower half area, the wafer stage 20 is moved up to ± D in the X direction.
/ 2, -D / 2 in the Y direction. Wafer stage 20
Is indicated by a wafer stage moving range 56.

Although the push-up unit was moved before starting the pickup of the pellet from the lower half area, the orientation of the pellet is not changed because the wafer stage 20 is not rotated. Therefore, there is no need to rotate the suction nozzle.

Thus, no matter which area the pellet is taken out, the orientation of the pellet does not change.
The pellet can be sucked without rotating the suction nozzle.

In both the upper half area and the lower half area, the wafer stage 20 moves ± D / 2 in the X direction and −D / 2 in the Y direction. Wafer stage 20 when removing pellets
Is D in the X direction and D / 2 in the Y direction. That is, the conventional wafer 2 is divided into two regions,
After picking up all the pellets from the upper half area,
The range of movement of the wafer stage 20 can be reduced to about the same level as when the wafer 2 is rotated by 180 degrees and all the remaining pellets are picked up.

Further, in the present embodiment, since it is not necessary to rotate the wafer stage 20, the wafer 2
When rotated by 80 degrees, the time required for this rotation can be reduced, and the production efficiency is improved, as compared with the conventional method in which it is necessary to apply a correction rotation (180 degrees rotation) corresponding to the rotation amount of the wafer 2 to the removed pellet. Can be done.

[0060]

As described above, according to the present invention,
Dividing each pellet obtained by dicing the wafer into a plurality of regions, without changing the direction of the pellet when taking out the pellets for each of the divided regions, that is, without the need for a suction nozzle rotation mechanism, etc. Pellets can be picked up, and the moving range of the wafer stage can be reduced. As a result, it is possible to improve the productivity and narrow the moving range of the wafer stage.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically illustrating the configuration of a pellet pickup device according to the present invention.

FIG. 2 is a diagram for explaining a method of equally dividing a wafer into four regions and picking up pellets for each region according to the first embodiment of the present invention.

FIG. 3 is a view for explaining a moving direction and a moving amount of a push-up unit according to the first embodiment of the present invention.

FIG. 4 is a view for explaining a method of equally dividing a wafer into two regions and picking up pellets for each region according to the second embodiment of the present invention.

FIG. 5 is a view for explaining a conventional method of equally dividing a wafer into four regions and picking up pellets for each region.

FIG. 6 is a diagram showing a state in which a pyramid collet attached to a tip of a suction nozzle appropriately suctions a pellet.

FIG. 7 is a view showing a state in which the pyramid collet cannot properly adsorb the pellet because the pellet is rotated by 90 degrees.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Push-up unit 12 Push-up unit moving means 14 Push-up unit driving means 20 Wafer stage 22 Wafer stage rotating means 32 Wafer stage moving means

Claims (4)

[Claims] A pellet stage that divides a group of pellets obtained by dicing a wafer into a plurality of regions and takes out the pellets for each of the divided regions; a wafer stage on which the wafer is mounted; A push-up unit for pushing up each pellet on the stage; a push-up unit moving means for moving the push-up unit to a predetermined position corresponding to each of the divided areas of the wafer; A wafer stage moving means for moving a wafer stage so as to sequentially move each of the pellets to a position to be pushed up by the push-up unit positioned at the predetermined position according to the region; and sequentially moving the wafer stage to the position to be pushed up. Drive the push-up unit to pick up each pellet Pellets pickup apparatus characterized by comprising a push-up unit driving unit. 2. The pellet pickup device according to claim 1, further comprising a wafer stage rotating means for rotating the wafer stage. 3. A pellet pick-up method in which a pellet group obtained by dicing a wafer is divided into a plurality of regions, and a pellet is taken out by using a push-up unit for each of the divided regions. The moving direction and the moving amount of the push-up unit when switching from one region to another region in a plurality of divided regions are formed by virtually moving the one region and the other region relative to each other. And determining a moving direction and a moving amount of the other region with respect to the one region when a rectangle circumscribing a virtual combined region of the one region and the other region has a minimum area. And the pellet pickup method. 4. Each of the pellets obtained by dicing the wafer is divided into four regions by an X axis and a Y axis orthogonal to each other at the center of the wafer, and each of the divided regions is pushed up by a unit. And picking up the pellets in the first area by sequentially moving the pellets in the first area to positions to be pushed up by the push-up unit by moving the wafer. Then, the pellets in the first area are sequentially picked up by the push-up unit. Next, the push-up unit is moved from the center of the wafer to an intersection point between the X axis or the Y axis and the outer periphery of the wafer. Moving the wafer to a point not in contact with the first area, and moving the wafer in substantially the same manner as when a pellet in the first area is picked up. The pellets present in the second area are sequentially moved to a position to be pushed up by the push-up unit, and the pellets in the second area are sequentially picked up by the push-up unit. Rotate 180 degrees, sequentially pick up the pellets in the third area in the same manner as when picking up the pellets in the second area, then return the push-up unit to the center of the wafer, A pellet pick-up method comprising sequentially picking up the pellets in the fourth region in the same manner as in the case where the pellets in the region are picked up.