JP3443193B2 - Pellet bonding equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pellet bonding apparatus used in a semiconductor manufacturing process.

[0002]

2. Description of the Related Art One of semiconductor manufacturing processes is a pellet bonding process using a pellet bonding apparatus. In other words, the suction nozzle of the pellet take-out mechanism takes out the pellets from the wafer ring unit installed on the wafer stage, places the pellets on the rotary table of the pellet position correcting mechanism, and then moves the rotary table as necessary. After being rotated to correct the displacement of the pellet, the suction nozzle of the bonding mechanism picks up the pellet on the rotary table and bonds it to the lead frame.

[0003]

In this conventional pellet bonding apparatus, as shown in FIG. 6 (A), the pellet 2 in the area A on the right half of the wafer 1 is taken out by the suction nozzle of the pellet taking-out mechanism. When the pellet 2 is placed on the rotary table 3 of the pellet position correcting mechanism, the position of the pellet 2 is detected by using the camera without rotating the rotary table 3 and, if necessary, After rotating the rotary table 3 to correct the rotation of the pellet 2, the pellet 2 on the rotary table 3 is bonded to the lead frame 4 by using the suction nozzle of the bonding mechanism.

However, as shown in FIG. 6 (B), the wafer stage on which the wafer ring unit is mounted is rotated by 180 degrees, and the pellets 2 in the region B of the remaining half of the wafer 1 are rotated.
When the pellets 2 are taken out by the suction nozzle and placed on the rotary table 3, the rotary table 3 is first placed at 180
After the rotation of the pellet 2 is detected, the position of the pellet 2 is detected by using a camera, the rotary table 3 is rotated as necessary to correct the rotation of the pellet 2, and then the pellet 2 is attached to the lead frame 4 by using a suction nozzle. Bonding.

As described above, when the pellet 2 in the area B of the wafer 1 is taken out, it is necessary to rotate the rotary table 3 by 180 degrees. Therefore, as shown by a chain line in FIG.
The rotation end timing of the rotary table 3 is delayed, so that the position (orientation) correction process of the pellet 2 and the bonding process of the pellet 2 by the bonding head are sequentially delayed. As a result, the pellet bonding work of the pellets 2 in the area A and the area B takes a long time as a whole.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a pellet bonding apparatus capable of performing pellet bonding work in a short time.

[0007]

Means for Solving the Problems The present invention is divided from the wafer
Installed wafer ring unit with separated pellets
With the possible wafer stage and pellet extraction position,
Pellets from the pellet group of the wafer ring unit
Pellet collection that takes out sequentially and transfers to the rotary table described later
The pellet take-out mechanism having a take-out mechanism and a rotary table.
Correct the position of pellets placed on this rotary table.
Pellet position correction mechanism and this pellet position correction machine
Take out the pellet whose position has been
With a bonding mechanism for bonding to the
The wafer stage is the same as the wafer ring unit.
The wafer is grouped at each angle by dividing the pellet group into multiple areas.
Ring unit can be rotated to correct the pellet position
The mechanism depends on whether or not the wafer ring unit is rotated.
Without rotating the rotary table in either forward or reverse direction by a predetermined angle.
The pellets by the bonding mechanism.
It is possible to correct so that the orientation of the pellets at the time of delivery is always the same .

According to the present invention, when the wafer stage is rotated by a predetermined angle or not, the rotary table of the pellet position correcting mechanism is rotated by a predetermined angle so that the direction of the pellet at the time of taking out the pellet by the bonding mechanism is always constant. It is set to the same.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a part of an embodiment of the pellet bonding apparatus according to the present invention. FIG. 2 is a plan view showing a positional relationship between a wafer and pellets in the pellet bonding apparatus of FIG. FIG. 3 is a process diagram showing a part of the pellet bonding process.

The pellet bonding apparatus 10 shown in FIG.
The lead frame 16 is manufactured by taking out a large number of pellets 13 separated one by one by dicing the wafer 12.
Is bonded to the island portion 17, and is configured to include a wafer stage 21, a pellet extraction mechanism 18, a pellet position correction mechanism 19, and a bonding mechanism 20.

Here, the wafer 12 is attached to an annular wafer ring 15 via an adhesive sheet 14, and is set on the wafer stage 21 as a wafer ring unit 11. Further, an orientation flat portion 22 for confirming the direction of the wafer 12 is formed on the wafer 12.

The wafer stage 21 is mounted on an XY table, the wafer ring unit 11 is installed, and the adhesive sheet 14 of the wafer ring unit 11 is stretched to expand the gap between the pellets 13.
The pellet transfer 23 makes it easy to take out the pellet 13. Furthermore, this wafer stage 21
2A and 2B, when the pellet group (wafer 12) of the wafer ring unit 11 is divided into an M region on the right half and an N region on the left half, ,
When the removal of the pellet group in either area is completed, the wafer ring unit 11 is rotated 180 degrees about the central axis O, and the other area is positioned at the extraction position 23B of the pellet transfer 23 in the pellet extraction mechanism 18.

The pellet take-out mechanism 18 shown in FIG.
A pellet transfer 23 for taking out the pellets 13 from the wafer stage 21 on which the wafer ring unit 11 is installed is provided. The pellet transfer 23 is equipped with a suction nozzle 23A. The suction nozzle 23A sucks the pellet 13 shown in FIG. 1 and rotates 90 degrees as shown in FIGS. 2 (A) and 2 (B). The position correction mechanism 19 is placed on the rotary table 24.

As shown in FIG. 1, the pellet position correcting mechanism 19 detects the rotary table 24 on which the pellets 13 taken out by the pellet transfer 23 are placed, and the position of the pellets 13 on the rotary table 24. And a detection camera 25 that does this. Turntable 24
Is installed between a guide rail 26 that guides the conveyance of the lead frame 16 and the wafer stage 21, and a detection camera 25 is arranged vertically above this. The pellet position correcting mechanism 19 properly corrects the position of the pellet 13 as described later in detail.

The bonding mechanism 20 has a bonding head 27 having a suction nozzle 27A at its tip,
The suction nozzle 27A of the bonding head 27 picks up the pellet 13 whose position has been corrected in the same direction on the rotary table 24, and uses an adhesive or the like for the island portion 17 of the lead frame 16 which is conveyed along the guide rail 26. And bond. Bonding head 27
As shown in FIG. 3, the bonding process of the pellets 13 is performed after the pellet position correcting process by rotating the rotary table 24.

The orientation of the pellets 13 on the wafer stage 21, the pellet transfer direction by the pellet transfer 23 and the bonding head 27, the lead frame 1
The relationship between the bonding directions of the pellets 13 in No. 6 is as shown in FIG.
After being taken out at 3 A and placed on the rotary table 24, the rotary table 24 is set to be rotated by −90 degrees so that the orientation of the pellets 13 is corrected and the bonding head 27 can pick up the pellets 13. In the case of the embodiment, first, the direction of the pellets 13 in the pellet group is set to be the same as the bonding direction of the pellets 13 in the lead frame 16.

The rotary table 24 is shown in FIGS.
As shown in, it is configured to be rotatable in forward and reverse directions. That is, when the pellet transfer 23 is taking out the pellets 13 in the M region of the wafer 12, the rotary table 24 rotates −90 degrees. Also, pellet transfer 2
When 3 is taking out the pellets 13 in the N region of the wafer 12, the rotary table 24 rotates by +90 degrees. In this way, the rotary table 24 moves in the direction in which the rotation amount is small.
By rotating 90 degrees, the orientations of the pellets 13 are aligned in the same direction, and then the positional shift of the pellets 13 is detected by the detection camera 25. Then, if necessary, the rotary table 24 is corrected and rotated based on the detected value, and the pellet 13 on the rotary table 24 is fixed to the bonding head 2.
It is corrected to a position where the pellet 13 is bonded to the lead frame 16 properly.

In this rotary table 24, as shown in FIG. 3, the pellet transfer 23 is a rotary table 24.
The rotation of the pellet 13 is started at a time point a after the pellet 13 is placed thereon, and the detection of the pellet position by the detection camera 25 is started at a time point b when the rotation of the rotary table 24 is completed. Further, the bonding head 27 starts to descend from the time point c when the detection of the detection camera 25 ends, and after the time point d when the correction rotation of the turntable 24 based on the detection result of the detection camera 25, which is performed as necessary, ends. The pellets 13 are picked up from the rotary table 24 and bonded. Even if the pellet transfer 23 places the pellet 13 on the rotary table 24, the pellet transfer 23 detects the pellet position until the point e when the pellet transfer 23 returns to the original position.
This is performed after the waiting time T has passed in order to block the field of view of No. 5.

According to the above embodiment, the rotary table 24
The pellet transfer 23 is the pellet 13 in the M area.
Even when taking out the wafer ring unit 11
Even when the pellet transfer 23 takes out the pellets 13 in the N region by rotating 180 degrees, the position (direction) of the pellets 13 placed on the rotary table 24 is corrected by rotating ± 90 degrees.

On the other hand, in the conventional example shown in FIG. 6, when the pellet transfer takes out the pellets 2 in the area A of the wafer 1, the rotary table 3 does not rotate, and the pellet transfer takes out the pellets 2 in the area B. At this time, the rotary table 3 is rotated 180 degrees to correct the position of the pellet 2 on the rotary table 3. In this conventional example, when the pellet 2 in the B area is being taken out, as shown by the alternate long and short dash line in FIG.
Since the pellet 2 cannot be bonded by the bonding head, the pellet bonding operation of the pellet 2 in the B region requires a long time. As described above, even when the pellet 2 in the area A in which the rotary table 3 does not rotate is taken out, the detection camera must wait at least the waiting time T until the pellet transfer returns to the original position every time the pellet is taken out. Therefore, it cannot be said that the working time can be shortened even in the bonding work of the pellet 2 in the area A.

On the other hand, in the above embodiment, since the pellet transfer 23 returns to the original position while the rotary table 24 is rotating ± 90 degrees, the detection camera 25 sets the waiting time T due to the return of the pellet transfer 23. The detection can be started immediately after the rotation of the rotary table 24 is completed without consideration. However, since the rotary table 24 only rotates ± 90 degrees, the rotation time is short. Therefore, both when the pellet transfer 23 is taking out the pellets 13 in the M region of the wafer 12 and when the pellets 13 are taking out the pellets 13 in the N region, the detection start timing by the detection camera 25 can be accelerated, and therefore the bonding head The pickup of the pellet 13 by the 27 can also be accelerated. As a result, M
The pellet bonding work for bonding the pellets 13 in the region and the N region can be performed in a short time as a whole.

Next, a second embodiment of the present invention will be described with reference to FIGS.
Will be explained. In the second embodiment, the first
The same parts as those in the embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the pellet bonding apparatus 30 according to the second embodiment, the wafer stage 31 is 90 degrees or 180 degrees.
The rotation table 32 of the pellet position correcting mechanism 19 is rotated in the order of 270 degrees, 270 degrees and 360 degrees.
It rotates to a rotation angle according to the rotation angle of.

That is, when the wafer stage 31 divides the pellet group of the wafer ring unit 11 into four areas of A area, B area, C area, and D area of 90 degrees in the same direction, this wafer ring is used. The unit 11 is rotated by 90 degrees about its central axis O to position each A area, B area, C area, and D area at the take-out position 23B of the pellet transfer 23 in the pellet take-out mechanism 18.

In this case, as shown in FIG.
After the pellets 13 in the area A are taken out by the adsorption nozzle 23A (FIG. 1) of the pellet transfer 23 and placed on the rotary table 32, the direction of the pellets 13 is changed by rotating the rotary table 32 by -45 degrees. It is set so as to be corrected and picked up by the bonding head 27. In the case of the embodiment, first, the direction of the pellets 13 of the pellet group is the pellets 13 of the lead frame 16.
The bonding direction is set to -45 degrees.

Further, the rotary table 32 is configured to be rotatable in forward and reverse directions, and a rotation amount necessary for correcting the position of the pellet is small in accordance with the area of the pellet group positioned at the take-out position 23B of the pellet transfer 23. The rotation direction is set to. That is, when the pellet transfer 23 takes out the pellets 13 in the area A, it rotates by -45 degrees (FIG. 4A), and when the pellet transfer 23 takes out the pellets 13 in the area B, it rotates by -135 degrees (FIG. 4B). When the pellet transfer 23 takes out the pellet 13 in the C region, it rotates by +135 degrees (FIG. 5A), and when the pellet transfer 23 takes out the pellet 13 in the D area, it rotates +45 degrees (FIG. 5B).

± 45 degrees of the rotary table 32 as described above,
The rotation of ± 135 degrees aligns the pellets 13 on the rotary table 31 in the same direction, and then the detection camera 25 detects the positional deviation of the pellets 13. Based on this detected value, the rotary table 32 is adjusted as necessary. Correction rotation. Then, the pellet 1 on the rotary table 32
3 is the lead frame 1 by the bonding head 27.
6 is properly bonded.

Also in the second embodiment, since the pellet transfer 23 returns to the original position while the rotary table 32 rotates ± 45 degrees or ± 135 degrees, the detection camera 25 ends the rotation of the rotary table 32. Detection can start immediately afterwards. However, since the rotary table 32 is rotated by ± 135 degrees at the maximum, the rotation time is shorter than that in the conventional case of rotating 180 degrees. As a result of these, the pellet transfer 23 causes the pellet group A area, B area, C area or D area.
Even when the pellets 13 are taken out from any one of the areas, the detection start timing of the detection camera 25 and the pickup timing of the pellets 13 by the bonding head 27 can be accelerated, and the pellet bonding work can be performed in a short time as a whole. .

In the above embodiment, the pellet 13 is first
When the pellets 13 are taken out from the M area and the A area, which are areas from which the rotary table 2 is removed.
4 and 32 were rotated -90 degrees and -45 degrees, respectively, to correct the rotation of the pellet 13.
The rotation angle is not limited to the above embodiment. In short, after the pellet transfer 23 takes out the pellets 13 from the pellet group in the wafer ring unit 11 and places them on the rotary tables 24 and 32, the rotary table 2
4, 32 is rotated and the orientation of the pellet 13 is corrected,
Such a series of operations is performed on all the pellets 13 taken out from the pellet group, the orientation of the pellets 13 on the wafer stages 21 and 31, the pellet transfer direction by the pellet transfer 23 and the bonding head 27, and the pellets on the lead frame 16. It suffices if the respective relationships of 13 bonding directions are set. If this relationship is satisfied, the number of divided regions of the pellet group and the rotation angle of the pellet transfer 23 may be the numbers and angles other than those in the embodiment, and regarding the transfer of the pellet 13 by the pellet transfer 23, the pellet transfer 23 Is the wafer stage 21, 3
A linear reciprocating motion between 1 and the pellet position correcting mechanism 19 may be used.

[0030]

As described above, according to the pellet bonding apparatus of the present invention, the pellet bonding work can be carried out in a short time.

[Brief description of drawings]

FIG. 1 is a perspective view showing a part of a first embodiment of a pellet bonding apparatus according to the present invention.

2A is a plan view showing the positional relationship between the wafer and the pellets when the pellet transfer takes out the pellets from the pellet group in the M region of the wafer in the pellet bonding apparatus of FIG. 2B is a plan view showing the positional relationship between the wafer and the pellets when the pellet transfer takes out the pellets from the pellet group in the N region of the wafer.

FIG. 3 is a process drawing showing a part of a pellet bonding process.

FIG. 4 (A) is a plan view showing the positional relationship between the wafer and the pellets when the pellet transfer takes out the pellets from the pellet group in the area A in the second embodiment of the pellet bonding apparatus. 4B is a plan view showing the positional relationship between the wafer and the pellets when the pellet transfer takes out the pellets from the pellet group in the B region.

FIG. 5A is a plan view showing a positional relationship between wafers and pellets when a pellet transfer takes out pellets from a pellet group in a region C in the second embodiment of the pellet bonding apparatus, FIG. 5B is a plan view showing the positional relationship between the wafer and the pellets when the pellet transfer takes out the pellets from the pellet group in the D region.

FIG. 6 is a plan view showing a positional relationship between a wafer and pellets in a conventional pellet bonding apparatus.

[Explanation of symbols]

10 Pellet bonding equipment 11 Wafer ring unit 12 wafers 13 pellets 16 lead frame 18 Pellet take-out mechanism 19 Pellet position correction mechanism 20 Bonding mechanism 21 Wafer stage 23 Pellet transfer 23B Pellet take-out position 24 turntable 27 Bonding head

Claims (5)

(57) [Claims] 1. A wafer stage on which a wafer ring unit including pellets separated from a wafer can be installed, and pellets are sequentially taken out from a pellet group of the wafer ring unit at a pellet take-out position and transferred to a rotary table described later. A pellet position correcting mechanism that has a pellet take-out mechanism and a rotary table, and corrects the position of the pellets placed on the rotary table by the pellet take-out mechanism, and takes out the pellets whose position is corrected by the pellet position corrector mechanism. And a bonding mechanism for bonding to a lead frame, the wafer stage enables the wafer ring unit to rotate at each angle obtained by dividing the pellet group of the wafer ring unit into a plurality of regions, and the pellet position correcting mechanism. Is the rotation of the wafer ring unit Regardless of the presence or absence, the rotary table can be rotated by a predetermined angle in either forward or reverse directions so that the direction of the pellets at the time of taking out the pellets by the bonding mechanism can be corrected so as to be always the same. . 2. The pellet position correcting mechanism allows the rotation direction of the rotary table to be selected according to the area of the pellet group positioned at the pellet extracting position of the pellet extracting mechanism by the rotation of the wafer ring unit. Pellet bonding equipment. 3. A pellet position correcting mechanism, the rotary table rotated by a predetermined angle in correcting the orientation of the pellets, according to claim 1, selectable rotation direction rotation amount small of the rotary table required for the modified Pellet bonding equipment. 4. The wafer stage, when the pellet group of the wafer ring unit is divided into M and N regions,
When the wafer ring unit is rotated 180 degrees, the M and N regions are sequentially positioned at the pellet extraction position of the pellet extraction mechanism, and the pellet position correction mechanism uses the pellet extraction mechanism to extract the pellets from the M region. according to claim 1, in which rotates 90 degrees rotary table in opposite direction in the case taken from said N region
3. The pellet bonding apparatus according to any one of 3 above. 5. The wafer stage rotates the wafer ring unit by 90 degrees when the pellet group of the wafer ring unit is divided into four regions of A, B, C, D in the circumferential direction by 90 degrees in sequence. Then, the four areas A, B, C, and D are sequentially positioned at the pellet take-out position of the pellet take-out mechanism, and the pellet position correction mechanism uses the pellet take-out mechanism when the pellets are taken out from the area A. The rotary table is rotated by 45 degrees in one direction, the rotary table is rotated by 135 degrees in the one direction when taken out from the area B, and the rotary table is taken out when taken out from the area C. If it is taken out from the D area by rotating it 135 degrees in the other direction, move the rotary table in the other direction.
The pellet bonding apparatus according to any one of claims 1, 2 and 3 , which is rotated by 45 degrees.