JPH08124994A - Pellet sorter - Google Patents

Abstract

PURPOSE: To improve the accuracy of thrust-up of a pellet, and to enhance the rate of storage of the pellets by recognizing a cutting line formed onto a wafer on the basis of the reflected image of light and correcting a stage, on which the wafer is placed, and the place of thrust-up of the pellet after dicing. CONSTITUTION: The positional displacement of a camera 2 and a wafer 1 is arithmetically operated by an arithmetic section 5 on the basis of information regarding cutting lines 1a formed on the wafer 1 obtained by a recognizing section 4 connected to the camera 2, into which the reflected image of visible light is taken a stage 8, on which the wafer 1 is placed, is moved by a driving section 9, and the places of thrust-up by the needles 11 of pellets 10 after dicing are corrected. Accordingly, the accuracy of thrust-up of the pellets is improved, thus enhancing the rate of storage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pellet classifying apparatus for classifying pellets after dicing a semiconductor wafer (hereinafter simply referred to as "wafer") in semiconductor manufacturing technology, and more particularly to improving the accuracy of pushing up individual pellets. ,
The present invention relates to a pellet classifying apparatus that improves the packing rate of pellets.

[0002]

2. Description of the Related Art The techniques described below are for studying the present invention,
The present invention was studied by the present inventors upon completion, and its outline is as follows.

In a pellet sorting apparatus for pushing up pellets on a wafer after dicing with a needle, which is a needle-like member, to sort the pellets into individual pellets,
An imaging unit such as a camera automatically recognizes the cutting line on the wafer, which allows the camera and the wafer (pellet) to be recognized.
After aligning the positions, the pellets are pushed up.

Here, the automatic recognition of the cutting line is performed by irradiating the cutting line formed on the wafer with light from a light source installed above the cutting line to form an image formed by reflected light and scattered light of the light. By performing the binarization processing, the θ correction of the wafer and the coordinate origin position are automatically calculated and corrected.

The pellet sorter (also referred to as a die sorter) is described, for example, on pages 134 to 137, "Latest semiconductor factory automation system integrated technology compilation" published by Science Forum Co., Ltd., issued July 25, 1984. ing.

[0006]

However, in the above-mentioned technique, when the needle is replaced for regular replacement, the mounting position of the needle may be deviated, resulting in the center of the camera and the center of the needle. Since the needles and the pellets are misaligned, the positions of the needle and the pellet are also misaligned, which causes a problem of worsening the pellet push-up condition.

That is, the pellet is pushed up diagonally,
As a result, there is a problem that the collet is also attracted in an oblique state and is not accommodated in the tray or is not attracted by the collet.

[0008] Therefore, an object of the present invention is to provide a pellet classifying apparatus which improves the pushing-up accuracy of pellets and improves the accommodation rate of pellets.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0010]

Of the inventions disclosed in the present application, a representative one will be briefly described below.
It is as follows.

That is, the pellet classifying apparatus according to the present invention comprises a light source for irradiating light onto a wafer, an image pickup section for taking in a reflected image of the light, and a cutting line connected to the image pickup section and formed on the wafer. Recognition unit, a stage for mounting the wafer through a wafer fixing member for mounting the wafer, a needle that is a needle-shaped member that pushes up the pellet after dicing, and an automatic offset that corrects the push-up position of the pellet. And means.

Further, the automatic offset means is means for moving the stage based on a displacement amount between a predetermined position of the image pickup section and a predetermined position of the needle.

The amount of deviation is measured by moving the position of a reticle, which is an index set in the visual field image by the image pickup unit, according to the position of the needle.

A needle guide for pressing the wafer fixing member and guiding the needle when the pellet is pushed up is installed.

[0015]

According to the above-mentioned means, the position of the pellet and the position of the needle can be matched by having the automatic offsetting means for correcting the push-up position of the pellet.

As a result, the accuracy of pushing up the pellets can be improved, and as a result, the packing rate of the pellets in the tray can be improved.

Further, since the automatic offset means is means for automatically moving the stage based on the amount of deviation between the predetermined position of the image pickup portion and the predetermined position of the needle, the correction operation can be simplified. You can

Further, since the displacement amount is measured by moving the position of the reticle, which is an index set in the visual field image by the image pickup unit, in accordance with the position of the needle, the displacement is measured by a simple structure. The amount of deviation can be measured.

Since the needle guide is installed, the needle guide presses the wafer fixing member when pushing up the pellet, so that the needle can easily break through the wafer fixing member.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a conceptual diagram showing an embodiment of the structure of a pellet classifying device according to the present invention, and FIG. 2 is a conceptual diagram showing an example of a method of measuring the offset deviation amount of an image pickup unit by the pellet classifying device according to the present invention. (A) and (c) are field-of-view images by the imaging unit, (b) and (d) are partial cross-sectional views, and FIG. 3 shows an example of the procedure of the pellet conveying method by the pellet sorting apparatus of the present invention. FIG.

First, the structure of the pellet classifying apparatus of this embodiment will be described. A light source 3 for irradiating the wafer 1 with light such as visible light, a camera 2 as an image pickup unit for capturing a reflected image of the visible light, and A recognition unit 4 which is connected to the camera 2 and recognizes a cutting line 1a formed on the wafer 1, and a cutting line 1 recognized by the recognition unit 4
a calculation unit 5 for calculating the wafer position shift between the camera 2 and the wafer 1 based on a, a stage 8 for mounting the wafer 1 via a wafer attaching tape 6 which is a wafer fixing member for attaching the wafer 1 and a frame 7. A drive unit 9 that moves the stage 8 to align the camera 2 and the wafer 1 based on the calculation result of the calculation unit 5, a needle 11 that is a needle-like member that pushes up the pellet 10 after dicing, and a needle 11 when pushing up. Needle guide 12 that holds wafer sticking tape 6 and guides needle 11
And an automatic offset means 13 for correcting the push-up position of the pellet 10, and a collet 15 for vacuum-sucking the pushed-up pellet 10 and transporting it to the tray 14.

The pellet sorting apparatus is provided with four needles 11, but the number of needles is not particularly limited.

The camera 2 is provided with a reticle 2a (including a crosshair 2b) which is an index in the visual field image 2c. For example, when the reticle 2a is moved within the visual field image 2c, it is placed in the recognition section 4. The moving distance can be instantly displayed on the monitor 4a or the like.

Here, the wafer attaching tape 6 has a thickness of 9
The wafer 1 before being diced is a tape member having a thickness of about 0 μm, and the wafer 1 is diced by attaching the wafer attaching tape 6 to the wafer 7 and further attaching the wafer attaching tape 6 to the frame 7. At this time, since the wafer attaching tape 6 is not cut, the wafer 1 after dicing remains on the wafer attaching tape 6.

After that, the dicing wafer 1 is still attached to the wafer attaching tape 6, and the frame 7
Each of them is mounted on the stage 8 and the work of pushing up the individually cut pellets 10 is performed there.

The needle guide 12 is, for example, a member made of metal or the like, and holds the wafer sticking tape 6 when pushing up the pellet 10 and guides the operation of the needle 11.

The collet 15 is, for example, a rubber member, and the suction surface is a pyramid having a concave shape.

This is a shape for preventing the surface of the pellet 10 from being damaged when the pellet 10 after being pushed up is adsorbed. The pellet 10 is adsorbed by vacuum adsorption, and then the tray 10 is adsorbed. 14
It is a member that conveys to.

Next, a method of measuring the offset deviation amount of the image pickup unit, a method of pushing up the pellets, and the transportation thereof by the pellet classifying apparatus of this embodiment will be described.

First, the dicing wafer 1 is conveyed to the stage 8 together with the frame 7 while being fixed on the wafer sticking tape 6, and the frame 7 is fixed at a predetermined position on the stage 8.

Thereafter, the light source 3 emits visible light to the wafer 1.
The upper cutting line 1a is irradiated and the camera 2
The reflection image is taken in by and the information of the reflection image is binarized in the recognition unit 4 connected to the camera 2 so that the cutting line 1a on the wafer 1 is processed.
Recognize the position of.

Subsequently, based on the information on the position of the cutting line 1a, the arithmetic unit 5 calculates the wafer position deviation between the camera 2 and a predetermined position of the wafer 1 (for example, the orientation flat of the wafer 1).

The position of the camera 2 can be aligned with the predetermined position of the wafer 1 by moving the stage 8 by the drive unit 9 based on the result of this calculation.

After that, the visual field image 2c installed on the camera 2
Using the reticle 2a, which is an index in the above, the offset amount 16 of the offset between the camera 2 and the needle 11 is measured in the visual field image 2c by the camera 2.

This is because, in the field-of-view image 2c of the camera 2, the predetermined position of the camera 2 is set as the origin position of the reticle 2a, and when the reticle 2a is moved from that position, the reticle 2 is moved.
Since the horizontal and vertical movement distances from the origin position of a are instantly displayed on the monitor 4a or the like installed in the recognition unit 4, the reticle 2a is moved to a predetermined position of the needle 11 (for example, four needles). It is possible to measure the offset deviation amount 16 between the camera 2 and the needle 11 by adjusting the position to the center position 11).

Not only the reticle 2a but also the crosshair 2
Even if b is used, the shift amount 16 can be measured as in the case of the reticle 2a.

Here, for example, as shown in FIGS. 2 (a) and 2 (b), the origin position of the reticle 2a and the four needles 1
When the center position of 1 is aligned, the shift amount 16 becomes zero (0), and the pellet 10 is pushed up as it is. At this time, since the needle guide 12 presses the wafer attaching tape 6, the needle 11 can easily break through the wafer attaching tape 6.

Then, as shown in FIG.
Is picked up and conveyed by the collet 15, and the tray 1
Store in 4.

Further, as shown in FIGS. 1 and 2C and 2D, the origin position of the reticle 2a and the four needles 1
When the shift amount 16 is generated between the center position of 1 and the needle 11, the positions of the needle 11 and the pellet 10 are also shifted. Therefore, first, the information of the shift amount 16 is transmitted to the automatic offset means 13. As a result, the automatic offset means 13 shifts by 1
Move stage 8 by the same amount as 6. As a result, the pellet 10 (wafer 1) on the stage 8 also moves by the displacement amount 16, so that the position of the pellet 10 and the position of the needle 11 can be aligned.

The automatic offset means 13 is based on the position data of the individual pellets 10 on the wafer 1 input in advance (for example, the coordinate position data of all the pellets 10 in the wafer map input in advance). By using the shift amount 16, the shift amount 16 of all the pellets 10
Is calculated, and the stage 8 is moved by the displacement amount 16 before being pushed up.

Thus, the positions of all the pellets 10 and the positions of the needles 11 can be matched before pushing up.

Thereafter, as shown in FIG. 3, the pellets 10 that have been pushed up are vacuum-sucked by the collet 15, and further conveyed to the tray 14 to be accommodated therein.

According to the pellet classifying apparatus of this embodiment, the following effects can be obtained.

That is, by having the automatic offset means 13 for correcting the push-up position of the pellet 10,
The position of the pellet 10 and the position of the needle 11 can be matched.

As a result, the accuracy of pushing up the pellets 10 can be improved, and as a result, the accommodation rate of the pellets 10 in the tray 14 can be improved.

Since the accuracy of pushing up the pellets 10 can be improved, the smaller the size of the pellets 10, the more effective the automatic offsetting means 13 of the pellet classifying device.

Further, the automatic offset means 13 uses the stage 16 based on the deviation amount 16 between the position of the needle 11 and the predetermined position of the camera 2 which is the image pickup section (the position of the reticle 2a in the visual field image 2c of the camera 2). Since 8 is automatically moved, the correction operation can be simplified.

Furthermore, since the displacement amount 16 is measured by moving the position of the reticle 2a, which is an index, in accordance with the position of the needle 11, the displacement amount 16 can be measured with a simple structure.

Since the needle guide 12 is installed, the needle guide 12 presses the wafer sticking tape 6 when the pellet 10 is pushed up.
The needle 11 can easily break through the wafer sticking tape 6.

As a result, the operation of pushing up the pellet 10 can be performed accurately and smoothly.

The invention made by the present inventor has been specifically described above based on the embodiments, but the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, in the pellet classifying apparatus described in the above embodiment, the pellets after being pushed up are vacuum-adsorbed by the collet, conveyed, and then accommodated in the tray. However, the pellet classifying apparatus individually cuts the pellets. It may just push up the pellets formed. in this case,
Although a pellet conveying device for conveying the pellets after being pushed up is separately required, the pellet sorting device has an automatic offset means, so that the pellet pushing up accuracy is improved similarly to the pellet sorting device described in the embodiment. You can

[0054]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

(1). By having the automatic offset means for correcting the push-up position of the pellet, the position of the pellet and the position of the needle can be matched.

As a result, the accuracy of pushing up the pellets can be improved, and as a result, the packing rate of the pellets in the tray can be improved.

(2). Since the pellet pushing-up accuracy can be improved, the smaller the pellet size is, the more effective the automatic offsetting means is.

(3). Since the automatic offset means automatically moves the stage based on the amount of deviation between the predetermined position of the imaging section and the predetermined position of the needle, the correction operation can be simplified.

(4). Since the amount of deviation is measured by moving the position of the reticle, which is an index set in the visual field image by the imaging unit, according to the position of the needle, the amount of deviation can be measured with a simple structure. You can

(5). Since the needle guide is installed, the needle guide presses the wafer fixing member when the pellet is pushed up, so that the needle can easily break through the wafer fixing member.

As a result, the work of pushing up the pellets can be carried out accurately and smoothly.

[Brief description of drawings]

FIG. 1 is a structural conceptual diagram showing an embodiment of the structure of a pellet sorting apparatus according to the present invention.

FIG. 2 is a conceptual diagram showing an example of a method of measuring an offset deviation amount of an imaging unit by the pellet classifying device of the present invention,
(a), (c) is a field-of-view figure by an image pick-up part, (b), (d) is a partial sectional view.

FIG. 3 is a partial cross-sectional view showing an example of a procedure of a pellet conveying method by the pellet sorting apparatus of the present invention.

[Explanation of symbols]

 1 wafer 1a cutting line 2 camera (imaging unit) 2a reticle (index) 2b crosshair (index) 2c visual field image 3 light source 4 recognition unit 4a monitor 5 arithmetic unit 6 wafer attachment tape (wafer fixing member) 7 frame 8 stage 9 drive Part 10 Pellet 11 Needle 12 Needle guide 13 Automatic offset means 14 Tray 15 Collet 16 Displacement amount

Claims (4)

[Claims] 1. A light source for irradiating a semiconductor wafer with light,
An image pickup unit that captures the reflected image of the light, a recognition unit that is connected to the image pickup unit and recognizes a cutting line formed on the semiconductor wafer, and the semiconductor wafer via the wafer fixing member that attaches the semiconductor wafer. A pellet sorting apparatus comprising: a stage to be mounted, a needle that is a needle-shaped member that pushes up a pellet after dicing, and an automatic offset means that corrects the push-up position of the pellet. 2. The pellet classifying apparatus according to claim 1, wherein the automatic offset means moves the stage based on a deviation amount between a predetermined position of the imaging section and a predetermined position of the needle. Pellet sorter characterized by the following. 3. The pellet sorter according to claim 2, wherein the displacement amount is obtained by moving the position of a reticle, which is an index set in the visual field image by the imaging unit, according to the position of the needle. Pellet sorter characterized by measuring. 4. The pellet classifying apparatus according to claim 1, wherein a needle guide that holds the wafer fixing member and guides the needle when the pellet is pushed up is installed. Pellet sorting equipment.