JPH118259A - Pickup method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To positively perform pickup by correcting the origin of the coordinate origin correction of a pickup move for each, preset pickup. SOLUTION: When the number of pickups reaches a preset count, a position deviation due to the punching of a small hole 5 can be corrected by performing origin matching of an origin mark 0 of a zero point pellet PO. For example, when the origin mark 0 is matched to a cursor G, the center G of an image- pickup device and the center of a projection unit match the origin mark 0. In this state, the effects of the punching of a number of small holes 5 has been corrected. Specifically, a deviation due to the punching has been eliminated or absorbed. A zero point has been newly matched. Therefore, by newly setting the position of the origin mark 0 in this state to the coordinate origin of the movement of the pickup, the center G of the image-pickup device can be moved relatively from the origin mark 0 to each pellet to be picked up hereafter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pickup method, and more particularly to a technique for picking up semiconductor pellets (hereinafter, referred to as pellets) in a semiconductor device manufacturing process from a wafer sheet. The present invention relates to those that are effective for use in picking up pellets.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, a pellet bonding method for bonding a pellet to a lead frame includes a step of sticking a stretchable wafer sheet to a semiconductor wafer (hereinafter, referred to as a wafer); A dicing step in which the wafer is cut into individual pieces; a wafer ring mounting step in which the wafer is held in a frame-shaped wafer ring via the wafer sheet in a state where the wafer sheet is stretched; There is a method including a pick-up step in which each pellet is sequentially peeled off from the wafer sheet by a pick-up tool and picked up, and a step in which the picked-up pellet is transferred onto a lead frame and bonded to the lead frame.

[0003] Further, electrical characteristics inspection is performed on the pellets in the wafer in a probe inspection process. In general, a reduction in manufacturing yield is prevented by performing a grading (grading) of the pellets based on the result of the electrical property inspection. In this case, when the pellets are picked up from the wafer sheet, the pellets are picked up for each grade.

Examples of the dicing technique include “Electronic Materials Nov. 1987, Separate Volume”, published on November 20, 1987 by the Industrial Research Council, Ltd., P40 to P45,
There is. Examples of the pellet bonding technology include “Electronic Materials December 1995 Separate Volume”, published on December 4, 1995, Industrial Research Institute, Inc., P80 to P8.
There are seven.

[0005]

In the above-described pickup method in which pellets are picked up from a wafer sheet for each grade, since the pellets are picked up irregularly from the wafer sheet, the position of the pellets becomes irregular. The rule changes, and the pellet positioning accuracy becomes unstable when each pellet is picked up. In the case of small pellets such as small-signal transistors and diodes, there is a problem that the pellet cannot be picked up. Revealed by the inventor.

An object of the present invention is to provide a pickup method capable of surely picking up fine pellets.

[0007] The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0008]

The outline of a typical invention among the inventions disclosed in the present application is as follows.

That is, after a semiconductor wafer adhered to an elastic wafer sheet is diced into a plurality of semiconductor pellets, the wafer sheet is stretched to separate the semiconductor pellets from each other. In the pick-up method in which the pick-up tools are sequentially picked up from the wafer sheet by the pick-up tools that are sequentially opposed to each other, the origin of the coordinate of the relative movement of the pick-up tool in each pick-up is at least one of the semiconductor pellets. When the number of pickups of the semiconductor pellets is set and reaches a predetermined number, an error in the current position of the origin with respect to the pickup tool is corrected.

According to the above-mentioned means, since the zero point correction of the origin is performed every preset number of times of pickup, the pellets are accurately positioned when picking up the pellets after the correction. Therefore, even fine pellets can be reliably picked up.

[0011]

FIG. 1 is a flowchart showing a pellet bonding method according to an embodiment of the present invention. FIG.
FIG. 3 is a plan view showing a relationship before and after stretching, and FIG.
Shows the state before stretching, and (b) shows the state after stretching. FIG. 3 shows a work, (a) is a plan view,
(B) is a front sectional view. FIG. 4 is a partially omitted perspective view showing a pellet bonding apparatus used in the pellet bonding method according to one embodiment of the present invention. FIG. 5 is an enlarged partial sectional view thereof. FIG. 6 et seq. Are explanatory diagrams for explaining the operation.

In the present embodiment, the pickup method according to the present invention is applied to a pellet bonding method for picking up a pellet for a small signal transistor from a wafer sheet and bonding it to a lead frame. This is performed by a pellet bonding apparatus shown in FIG.

In a so-called pre-process in the manufacturing process of the semiconductor device, an electronic circuit including transistor elements is formed on the wafer W for each pellet P as shown in FIG. The electrical characteristics of the wafer W are measured for each pellet P in a probe inspection process (not shown). Each pellet P is assigned a grade based on the measured electrical characteristics. At this time, the address of each pellet P is indicated by the XY coordinates with respect to the pellet P0 located at the center of the wafer W (hereinafter referred to as the origin pellet). An optically recognizable origin mark O is provided at the center of the origin pellet P0.

For example, assuming that the pellet indicated by P1 in FIG. 2 is a first pellet, P2 is a second pellet, P3 is a third pellet..., And Pn is an n-th pellet,
The address of the pellet P1 is (X0, Y5), the address of the second pellet P2 is (X1, Y5), and the third pellet P3
Is (X2, Y5), and the address of the nth pellet Pn is (Xn, Yn). And the first pellet P
The first grade is the first grade (hereinafter, referred to as A grade), the grade of the second pellet P2 is the second grade (hereinafter, referred to as B grade), and the third pellet P3 is the defective product (hereinafter, referred to as C grade). ... If the grade of the n-th pellet Pn is either A grade or C grade, the grade designation of each pellet P is as shown in Table 1 below, and a recording medium such as a floppy disk (not shown) ). In Table 1, the names of the first pellets P1, the second pellets P2,... Are for convenience, and only the address and the grade are actually recorded.

[0015]

The wafer sheet 1 (see FIG. 3) is adhered to the back surface of the wafer W which has been subjected to the probe inspection and the grade of each pellet is designated as described above, in a wafer sheet adhesion step (not shown). You. The wafer sheet 1 is made of a material having elasticity such as resin, and the wafer W
It is formed in a thin film shape having a diameter larger than that of the wafer W, and is adhered to the back surface of the wafer W using an appropriate adhesive. Subsequently, in a dicing step (not shown), the wafer W is divided into pellets P. At this time, since the wafer sheet 1 adhered to the back surface of the wafer W is not cut, the pellets P are not separated but are grouped together.

Next, in a stretching step (not shown), the work 3 shown in FIG. 3 is manufactured. That is, the wafer sheet 1 to which the wafer W is adhered is disposed so as to face a frame of a wafer ring 2 formed of a circular ring having a larger diameter than the wafer W using a rigid material such as stainless steel. Subsequently, it is stretched radially outward, and its outer peripheral portion is fixed to the wafer ring 2. At this time, since the wafer W adhered to the wafer sheet 1 is divided into the respective pellets P, the adjacent pellets P, P are separated with the elongation of the wafer sheet 1 and the position between the pellets is changed as shown in FIG. It will change before and after stretching as compared by (a) and (b).

Here, as shown in FIG. 2A, assuming that the width of the pellet P in the X direction is a and the width of the pellet P in the Y direction is b, the center O of the nth pellet Pn before stretching is obtained.
The distance e in the X direction and the distance f in the Y direction with respect to the origin mark O of n are obtained by the following equations, respectively. In the formula, Xn is an X coordinate value (integer) of the address of the n-th pellet Pn, and Yn is Y of the address of the n-th pellet Pn.
It is a coordinate value (integer).

E = a × Xn... F = b × Yn... For example, the distance e2 in the X direction of the second pellet P2 is a × 1 from Table 1 and the above equation, and Distance f
2 is b × 5 from Table 1 and the above equation. That is, before the enlargement, the position of the center of each pellet P can be simply obtained by multiplying the address value of each pellet by the size of the pellet.

After the enlargement, the positions of the pellets relatively move, so that the position of the center of each pellet P cannot be simply obtained by multiplying the address value of each pellet by the size of the pellet. However, the diameter of the wafer before stretching is d, and the diameter of the wafer after stretching is D
Then, the distances E and Y in the X direction of the center On of the n-th pellet Pn with respect to the origin mark O after stretching are obtained.
The distance F in the direction is obtained by the following equation and respectively. In the formula, Xn is the X coordinate value of the address of the n-th pellet Pn, Yn is the Y coordinate value of the address of the n-th pellet Pn, and D / d is the magnification.

E = a.times.Xn.times.D / d F = b.times.Yn.times.D / d For example, the distance E2 in the X direction of the second pellet P2 is calculated from the above Table 1 and the above equation. × 1 × D / d, and the distance F2 in the Y direction is b × 5 × D
/ D. That is, the position of the center of each pellet P after stretching can be obtained by multiplying the address value of each pellet, the size of the pellet, and the enlargement ratio. That is, the pellets P can be picked up from the stretched wafer sheet 1 for each grade based on the data in Table 1.

The work 3 manufactured as described above is sent to a pellet bonding step as a pickup step together with a recording medium (not shown) such as a floppy disk on which the data shown in Table 1 is recorded. In the pellet bonding step, each pellet P is designated based on the address data and grade designation data of each pellet obtained from the recording medium using the pellet bonding apparatus 10 shown in FIGS. Each grade is picked up from the work 3 and bonded to each lead frame 4.

The pellet bonding apparatus 10 has a feeder (not shown) for feeding the lead frame 4 at a pitch. An XY table 11 is controlled by a controller 12 at a position on the feeder corresponding to the lead frame 4 so that the XY table is controlled. It is equipped to be moved in the direction. The recording medium described above is mounted on the controller 12. The work 3 is detachably attached to the XY table 11 by the attachment 13. The wafer ring 2 of the work 3 is fixed to the XY table 11 by the fixture 13, and the wafer sheet 1 of the work 3 is pushed up from the upper surface of the wafer ring 2 by the push-up ring 14. .

Immediately below the work 3 on the XY table 11, a protrusion unit 15 as a pickup tool is provided. The push-up unit 15 includes a push-up guide 16 and a push-up pin 17. With the upper surface of the push-up guide 16 in contact with the wafer sheet 1, the push-up pin 17 pushes up the pellet P from the wafer sheet 1. It is configured to be peeled off. Work 3 on XY table 11
Immediately above the camera, an imaging device 18 such as a television camera is installed vertically downward, and the center of the imaging surface of the imaging device 18 coincides with the center of the push-up pin 17. An image recognition device 19 is electrically connected to the imaging device 18.
The image recognition device 19 transmits a recognition result to the controller 12 as described later.

A bonding head 20 controlled by the controller 12 is provided on one side of the XY table 11, and a bonding arm 21 controlled by the controller 12 is supported on the XY table 11. A collet 22 is attached to the tip of the bonding arm 21 vertically downward. The collet 22 picks up the pellet P pushed up from the work 3 by the suction pin 17 by vacuum suction and holding.
Subsequently, the pellet P is transported onto the lead frame 4 for bonding.

Next, taking as an example a case where A-grade pellets are sequentially picked up and bonded, pellet bonding in which pellets are pellet-bonded for each grade from the work having the above-described configuration by the pellet bonding apparatus 10 having the above-described configuration. The method will be described.

For example, when the first pellet P1 of the A grade is picked up, the XY table 11 is operated by a command from the controller 12 to obtain the signal shown in FIG.
As shown in FIG. 5, the center G (hereinafter, sometimes referred to as a cursor) of the imaging device 18 moves relatively from the origin mark O of the origin pellet PO to the center O1 of the first pellet P1 (actually, the work piece). The third side moves.) That is, the cursor G moves from the origin mark O of the origin pellet PO to the center O1 of the first pellet P1 by the distance E1 and the distance F1 obtained by the above Table 1 and the above formula.
Are only moved relatively. By the way, the first pellet P1
Is "0", the distance E1 is "0". In addition, since the center of the protrusion unit 15 is coincident with the center G of the imaging device 18, the center G of the imaging device 18 is substantially the same as the center of the protrusion unit 15.

Here, as shown in FIG. 6 (b), in the image H1 of the first pellet P1 formed by the image recognition device 19, the center O1 of the first pellet P1
Is shifted from the cursor G, the XY table 1
1 is operated so that the center O1 of the first pellet P1 is
Are relatively aligned with the cursor G. Controller 12
Measures the amount of movement of the XY table 11 in the X and Y directions at this time, thereby obtaining the first pellet P1.
Is calculated between the center O1 and the cursor G. Then, the controller 12 calculates the deviation amount in the X direction and the Y value necessary for correcting the error between the target value and the actual value.
Each is stored as a direction correction value. In the illustrated example of FIG. 6B, the correction value in the X direction is x1, and the correction value in the Y direction is y1.

The cursor G is positioned at the center O1 of the first pellet P1.
Is aligned, the center of the push-up unit 15 is aligned with the center O1 of the first pellet P1. Subsequently, the push-up pins 17 push up the first pellet P <b> 1 to separate the first pellet P <b> 1 from the wafer sheet 1 in a state where the push-up unit 15 is raised and the upper surface of the push-up guide 16 is in contact with the wafer sheet 1. The first pellets P <b> 1 that have been peeled off and pushed up from the wafer sheet 1 are vacuum-sucked and held by the collet 22 that is waiting in advance immediately above the push-up unit 15.

When the collet 22 receives the first pellet P1, the bonding arm 21 is operated and the collet 2
The first pellet P <b> 1 held by vacuum suction at 2 is moved right above the bonding position of the lead frame 4. Subsequently, the bonding arm 21 is
, And the first pellet P1 is bonded to the bonding position of the lead frame 4. When the first pellet P1 is bonded, the bonding arm 21 is raised and the collet 22 is in a state of waiting for the next operation.

On the other hand, when the push-up pins 17 transfer the first pellets P1 to the collet 22, the push-up unit 15 descends and stands by for the next operation. Here, since the push-up pins 17 pierce the wafer sheet 1 to push up the first pellets P1, small holes 5 as push-up marks are made at the center O1 of the first pellets P1 in the wafer sheet 1. It is in a state of being left.

Next, as shown in FIG. 7, when the fourth pellet P4, which is the second A-grade pellet, is picked up, the XY table 11 is operated by a command from the controller 12. Thereby, the center G of the imaging device 18 is relatively directly moved from the center O1 of the first pellet P1 to the center O4 of the fourth pellet P4. At this time, the controller 12 corrects the movement amount using the correction values x1 and y1 previously obtained for the first pellet P1.

Here, as shown in FIG. 7B, in the image H4 of the fourth pellet P4 formed by the image recognition device 19, the center O4 of the fourth pellet P4
Is shifted from the cursor G, the XY table 1
1 is operated, the center O of the fourth pellet P4 is
4 is relatively aligned with the cursor G. Controller 1
2 measures the amount of movement of the XY table 11 in the X and Y directions at this time, thereby obtaining the fourth pellet P.
The shift amount between the center O4 of the cursor 4 and the cursor G is calculated. Then, the controller 12 calculates the deviation amount in the X direction and the Y value necessary for correcting the error between the target value and the actual value.
Each is stored as a direction correction value. In the illustrated example of FIG. 7B, the correction value in the X direction is x4, and the correction value in the Y direction is y4.

The cursor G is positioned at the center O4 of the fourth pellet P4.
Is aligned, the center of the push-up unit 15 is aligned with the center O4 of the fourth pellet P4. Subsequently, the push-up pins 17 push up the fourth pellets P4 to separate them from the wafer sheet 1 in a state where the push-up unit 15 is raised and the upper surface of the push-up guide 16 is in contact with the wafer sheet 1. The fourth pellets P <b> 4 that have been peeled off and pushed up from the wafer sheet 1 are held by vacuum at a collet 22 that is standing by immediately above the push-up unit 15.

When the collet 22 receives the fourth pellet P4, the bonding arm 21 is operated and the collet 2
The fourth pellet P4 held by vacuum suction at 2 is moved right above the bonding position of the lead frame 4. Subsequently, the bonding arm 21 is
And the fourth pellet P4 is bonded to the bonding position of the lead frame 4. When the fourth pellet P4 is bonded, the bonding arm 21 is raised, and the collet 22 is in a state of waiting for the next operation.

On the other hand, when the push-up pin 17 transfers the fourth pellet P4 to the collet 22, the push-up unit 15 descends and stands by for the next operation. Here, since the push-up pins 17 pierce the wafer sheet 1 to push up the fourth pellet P4, a small hole 5 as a bump mark is formed at the position of the center O4 of the fourth pellet P4 in the wafer sheet 1. It is in a state of being left.

Next, when the fifth pellet P5, which is the third A-grade pellet, is picked up, XY
By operating the table 11 according to a command from the controller 12, the center G of the imaging device 18 is shifted from the center O4 of the fourth pellet P4 to the center O5 of the fifth pellet P5 (FIG. 4).
(See Reference). At this time, the controller 12 corrects the correction value x previously obtained for the fourth pellet P4.
The movement amount is corrected by using 4 and y4. Then, the above-described pickup operation and pellet bonding operation are repeated.

Thereafter, the center G of the imaging device 18 is shifted from the center On of the n-th pellet Pn picked up last time to the (n + 1) -th pellet (Pn + 1) to be picked up next time.
Are directly moved relative to the center O (n + 1) of the center position, thereby performing the pickup operation and the pellet bonding operation. The above-described operation of correcting the error between the target value and the actual value is also performed each time the center G of the imaging device 18 is relatively moved.

By the way, when the above operation is repeated,
As shown in FIG. 8A, a large number of small holes 5 are formed in the wafer sheet 1 as protrusion marks.
When a large number of small holes 5 are formed in the wafer sheet 1, the stretched wafer sheet 1 is deformed at a portion of the large number of small holes 5, so that the position of each pellet P is largely shifted. Become. When the cursor G is relatively directly moved from the twelfth pellet P12 to the thirteenth pellet P13 in such a state that the position of the pellet P is largely shifted, as shown in FIG. 8B. In addition, since the thirteenth pellet P13 cannot fit in the image H13, the image recognition device 19 cannot recognize the center O13 of the thirteenth pellet P13. As a result, the controller 12 cannot align the center of the push-up unit 15 with the center O13 of the thirteenth pellet P13, and thus cannot pick up the thirteenth pellet P13. Further, the correction operation between the target value and the actual value described above cannot be executed.

Therefore, in the present embodiment, as shown in FIG. 1, when the number of pickups reaches a preset number, the zero mark of the origin mark O of the origin pellet P0 is adjusted. Thus, the displacement caused by the perforation of the small hole 5 is corrected.

For example, when the number of pickups reaches ten, which is a preset number, the cursor G is moved from the twelfth pellet P12 to the origin pellet P0 as shown in FIG. Here, assuming that no displacement has occurred, the cursor G can return to the origin mark O of the origin pellet P0 based on the movement amounts E12 and F12 calculated from Table 1 and the above formula. it can.

However, when picking up the twelfth pellet P12, the cursor G cannot return to the origin pellet P0 depending on the movement amounts E12 and F12 since the above-described correction operation has been performed. Therefore, the controller 12 calculates the correction value x calculated for the twelfth pellet P12 in the calculation based on Table 1 and the above formula.
Correction to subtract 12 and y12 is performed. With this correction, as shown in FIG.
Can substantially return to the origin pellet P0.

However, even in the area of the origin pellet P0 in the wafer sheet 1, since the displacement has occurred due to the influence of the perforation of the many small holes 5, the cursor G is shifted from the origin mark O of the origin pellet P0. Would. Therefore, the controller 12 operates the XY table 11 to relatively align the origin mark O with the cursor G. The controller 12 calculates the amount of displacement between the origin mark O and the cursor G by measuring the amount of movement of the XY table 11 in the X and Y directions at this time. Then, the controller 12 uses the amount of deviation in the X direction correction value (hereinafter, referred to as a first X direction origin correction value) necessary to correct the deviation of the origin mark O, that is, the coordinate origin due to the perforation of the small hole 5. And a correction value in the Y direction (hereinafter referred to as a primary Y direction origin correction value). FIG.
In the illustrated example of (b), the primary X direction origin correction value is
Δx1, and the primary Y-direction origin correction value is Δy1.

When the origin mark O is aligned with the cursor G as described above, the center G of the imaging device 18 and the center of the push-up unit 15 coincide with the origin mark O. This state is a state in which the influence of the perforation of the plurality of small holes 5 is corrected, that is, a state in which the displacement due to the perforation is eliminated or absorbed, and is a state where a so-called zero point is newly set. Therefore, by setting the position of the origin mark O in this state as a new coordinate origin of the movement of the pickup, the center G of the imaging device 18 should be picked up from the origin mark O from Table 1 and the above formula. It can be relatively moved to each pellet P.

For example, from this state, the thirteenth pellet P1
When the pickup 3 is picked up, the XY table 11 is operated by a command from the controller 12 so that the cursor G is moved from the origin mark O of the origin pellet PO to the thirteenth pellet P13 as shown in FIG. It is moved to the center O13 by the distance E13 and the distance F13 determined by the above Table 1 and the above equation. Incidentally, since the X coordinate value of the thirteenth pellet P13 is “0”, the distance E13 is “0”.

Here, as shown in FIG. 10B, in the image H13 of the thirteenth pellet P13 formed by the image recognition device 19, the thirteenth pellet P1
When the center O13 of 3 is shifted from the cursor G,
By operating the XY table 11, the center O13 of the thirteenth pellet P13 is relatively aligned with the cursor G. The controller 12 measures the amount of movement of the XY table 11 in the X direction and the Y direction at this time, so that the center O13 of the thirteenth pellet P13 and the cursor G
Is calculated. Then, the controller 12 stores the deviation amount as a correction value in the X direction and a correction value in the Y direction required to correct the error between the target value and the actual value. In the example shown in FIG. 10B, the correction value in the X direction is x13, and the correction value in the Y direction is y13.

When the cursor G is aligned with the center O13 of the thirteenth pellet P13, the center of the push-up unit 15 moves to the first position.
The three pellets P13 are aligned with the center O13. Subsequently, the push-up pins 17 push up the thirteenth pellet P <b> 13 in a state where the push-up unit 15 is lifted and the upper surface of the push-up guide 16 is in contact with the wafer sheet 1, thereby separating the wafer sheet 1. The thirteenth pellet P13 peeled off and pushed up from the wafer sheet 1,
It is held by vacuum at the collet 22 which is waiting just above the protrusion unit 15 in advance.

Then, by performing the above-described pellet bonding operation, the thirteenth pellet P13 is bonded to the lead frame 4, and the projecting unit 15 enters a state of waiting for the next pickup operation. Also in this case, since the push-up pins 17 pierce the wafer sheet 1 to push up the thirteenth pellet P13, a small hole 5 as a push-up mark is formed at the position of the center O13 of the thirteenth pellet P13 in the wafer sheet 1. State.

Next, as shown in FIG. 11, when the fifteenth pellet P15 is picked up as the second pellet after the primary origin correction, the XY table 11
Is operated by a command from the controller 12, the center G of the imaging device 18 is directly relatively moved from the center O13 of the thirteenth pellet P13 to the center O15 of the fifteenth pellet P15. At this time, the controller 12 corrects the movement amount using the correction values x13 and y13 previously obtained for the thirteenth pellet P13.

Here, as shown in FIG. 11B, in the image H15 of the fifteenth pellet P15 formed by the image recognition device 19, the fifteenth pellet P1
When the center O15 of 5 is shifted from the cursor G,
By operating the XY table 11, the center O15 of the fifteenth pellet P15 is relatively aligned with the cursor G. The controller 12 measures the movement amounts of the XY table 11 in the X direction and the Y direction at this time, and thereby the center O15 of the fifteenth pellet P15 and the cursor G
Is calculated. Then, the controller 12 stores the deviation amount as a correction value in the X direction and a correction value in the Y direction required to correct the error between the target value and the actual value. In the illustrated example of FIG. 11B, the correction value in the X direction is x15, and the correction value in the Y direction is y15.

By performing the above-described pellet bonding operation, the fifteenth pellet P15 is bonded to the lead frame 4, and the push-up unit 15 is in a state of waiting for the next pickup operation. Also in this case, the push-up pins 17 pierce the wafer sheet 1 and
Since the pellet P15 is pushed up, a small hole 5 is formed as a protrusion mark at the position of the center O13 of the thirteenth pellet P13 in the wafer sheet 1.

Next, when the sixteenth pellet P16 is picked up as the third pellet after the primary origin correction, the XY table 11 is operated by a command from the controller 12 so that the imaging device 18 The center G is from the center O15 of the fifteenth pellet P15 to the sixteenth pellet P
It is relatively moved directly to the center O16 of 16 (see FIG. 11). At this time, the controller 12 corrects the movement amount by the correction values x15 and y16 previously obtained for the fifteenth pellet P15. Then, the above-described pickup operation and pellet bonding operation are repeated.

Thereafter, the center G of the imaging device 18 is shifted from the center On of the n-th pellet Pn picked up last time to the (n + 1) -th pellet (Pn +
By directly moving relative to the center O (n + 1) of 1), the pickup operation and the pellet bonding operation are performed. The above-described operation of correcting the error between the target value and the actual value is also performed each time the center G of the imaging device 18 is relatively moved.

Then, when the number of pickups after the primary origin correction reaches a preset number, for example, ten, the secondary origin correction for correcting the positional deviation of the origin mark O of the origin pellet P0. Is performed in the same procedure as the above-described first origin correction.

Thereafter, pickup and pellet bonding are repeatedly performed for the A-grade pellets P. When the pickup and the pellet bonding for the A-grade pellet P are completed, the pickup and the pellet bonding for the B-grade pellet P are sequentially performed. During this time, the origin correction described above is repeated in the third order, the fourth order, and so on.

According to the above embodiment, the following effects can be obtained. (1) Since the zero point correction of the origin of the work is automatically performed every preset number of pickups, the deformation of the work due to the pickup can be absorbed or eliminated in a timely manner, so that the pickup can be accurately performed. .

(2) By accurately picking up, even if it is a fine pellet, it is possible to reliably pick up and pellet-bond, so that a decrease in productivity of the fine pellet can be prevented. .

(3) Correction of the deformation of the work or stop of the operation of the pick-up device to perform zero point correction by absorbing or eliminating the deformation of the work and accurately performing the pick-up. It is possible to prevent the efficiency of the pick-up operation from lowering.

(4) Since the zero point correction of the origin of the work is automatically performed every time the pickup is performed, the pickup can be accurately performed in an irregular place. Therefore, the pickup for each grade is performed. Can be.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention. Needless to say.

For example, the origin pellet is not limited to being set at the center of the wafer, but may be set at a plurality of locations on the wafer as shown in FIG.

The relative movement between the work and the push-up pin is not limited to being executed by moving the work side, but may be executed by moving the work-up pin side.

The pickup and the pellet bonding are not limited to being performed for each grade, but are performed for each non-defective product and defective product.
In the case where varieties and the like are mixed, the process may be performed for each of the non-defective products, the defective products, and each of the varieties. It is needless to say that pickup and pellet bonding may be performed regularly in the order in which they are arranged.

The zero adjustment of the coordinate origin of the movement of the pickup is not limited to mechanically executing the actual movement of the center of the image pickup device to the origin mark, but is also performed by the controller using the correction value obtained from the displacement amount. May be configured to perform the correction.

The pick-up tool is not limited to being constituted by a protrusion unit.

In the above description, the case where the invention made by the present inventor is mainly applied to the pellet bonding method technology, which is the application field in the background, has been described. However, the present invention is not limited to this. The present invention can be applied to any pickup method used in a jig packing method for packing in a storage jig and a mounting method for mounting pellets directly on a printed wiring board. In particular, the present invention has an excellent effect when used for picking up fine pellets.

[0067]

The effects obtained by typical aspects of the invention disclosed in the present application will be briefly described as follows.

By performing the zero correction of the coordinate origin of the pick-up movement every preset number of pick-ups, the deformation of the work caused by the pick-up can be absorbed or eliminated in a timely manner, so that the pick-up can be performed accurately.

[Brief description of the drawings]

FIG. 1 is a process chart showing a pickup method according to an embodiment of the present invention.

FIG. 2 is a plan view showing a relationship before and after stretching.
(A) shows the state before stretching, and (b) shows the state after stretching.

3A and 3B show a workpiece, wherein FIG. 3A is a plan view and FIG.
Is a front sectional view.

FIG. 4 is a partially omitted perspective view showing a pellet bonding apparatus used in a pellet bonding method according to an embodiment of the present invention.

FIG. 5 is an enlarged partial sectional view thereof.

6A and 6B show a first step of the pickup method, in which FIG. 6A is an enlarged partial plan view and FIG. 6B is an image view.

FIG. 7 shows a second step of the pickup method, in which (a) is an enlarged partial plan view and (b) is an image view.

FIGS. 8A and 8B are explanatory diagrams for explaining the operation, in which FIG. 8A is an enlarged partial plan view and FIG. 8B is an image diagram.

9A and 9B show an origin correction step, in which FIG. 9A is an enlarged partial plan view and FIG. 9B is an image view.

10A and 10B show a first step after the primary origin correction, wherein FIG. 10A is an enlarged partial plan view and FIG. 10B is an image view.

11A and 11B also show a second step, wherein FIG. 11A is an enlarged partial plan view and FIG. 11B is an image view.

FIG. 12 is a plan view showing a work in a pellet bonding method according to another embodiment of the present invention.

[Explanation of symbols]

1 wafer sheet, 2 wafer ring, 3 work, 4
... lead frame, 5 ... small hole, 10 ... pellet bonding device, 11 ... XY table, 12 ... controller,
13 mounting fixture, 14 push-up ring, 15 projecting unit (pickup tool), 16 projecting guide, 17
... Pump pins, 18 ... Imaging devices, 19 ... Image recognition devices, 2
0: bonding head, 21: bonding arm,
22: collet, W: wafer, P: pellet, P0: origin pellet, O: origin mark, P1: first pellet, P
2: 2nd pellet, P3: 3rd pellet, Pn: nth pellet, a: X direction width of pellet, b: Y direction width of pellet.

Claims (10)

[Claims] 1. After a semiconductor wafer adhered to an elastic wafer sheet is diced into a plurality of semiconductor pellets, the wafer sheet is stretched to separate the semiconductor pellets from each other, and each semiconductor pellet is placed at its center. In the pickup method in which the pickup tool is sequentially picked up from the wafer sheet by the pickup tool that is sequentially opposed to at least one of the semiconductor pellet groups, the origin of the coordinate of the relative movement of the pickup tool in each of the pickups is set to at least one of the semiconductor pellets. A pick-up method, wherein when the set number of pick-ups of the semiconductor pellet reaches a predetermined number, an error in the current position of the origin with respect to the pick-up tool is corrected. 2. The correction of the origin is performed by moving the origin and the pickup tool relative to each other and then performing a movement for eliminating a positional deviation amount between the origin and the pickup tool. The pickup method according to claim 1, wherein 3. When correcting the origin, it is preferable that after the origin and the pickup tool are relatively moved, a correction value is calculated and corrected based on a positional shift amount between the origin and the pickup tool. The pickup method according to claim 1, wherein 4. The pickup method according to claim 1, wherein the correction of the origin is performed a plurality of times in the same semiconductor wafer. 5. The pickup method according to claim 1, wherein an error between a target value and an actual value is corrected for each pickup of each of the semiconductor pellets. 6. The semiconductor device according to claim 1, wherein the origin is set at a center of the semiconductor wafer.
Or the pickup method according to 5. 7. The semiconductor device according to claim 1, wherein the origin is set at a plurality of positions on the semiconductor wafer.
6. The pickup method according to 3, 4, or 5. 8. The semiconductor device according to claim 1, wherein the semiconductor pellet is provided with an origin mark indicating the origin.
The pickup method according to 3, 4, 5, 6, or 7. 9. The pickup according to claim 1, wherein the pickup is sequentially performed for each characteristic set for each of the semiconductor pellets. Method. 10. The pickup method according to claim 9, wherein the characteristic is a grade.