JP2003168655A - Dicing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dicing apparatus which has a measuring gauge that highly accurately measures the height-direction position of the upper face of a work and also measures the depth-direction position of a groove, always assures stable cut depth from the upper face of the work, and has a function capable of evaluating a machining state including the depth direction. <P>SOLUTION: This dicing apparatus comprises a laser displacement gauge 81 that measures the upper-face height position of a work W, and a cut-depth control means 83 that controls the cut depth of a rotary blade 21 based on the upper-face height position of the work measured by the laser displacement gauge 81. A mapping means 82 is also provided that forms a map of the height of the upper face of the work based on the measured result of the height- direction positions of a plurality of points of the upper face of the work by the laser displacement gauge 81. Based on the map, the cut depth control means 83 more precisely controls the cut depth of the rotary blade 21. Furthermore, the shape of the groove machined on the upper face of the work and the size of the chipping generated at the groove can be evaluated by the laser displacement gauge 81. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dicing device, and more particularly to a dicing device for performing groove processing and cutting processing on a work such as a semiconductor or an electronic component material.

[0002]

2. Description of the Related Art In a dicing device for grooving or cutting a work such as a semiconductor or an electronic component material, the work is processed by applying a grinding water with a thin grindstone called a blade which rotates at a high speed. In this dicing device, the spindle holding the blade is index-feeded in the Y-axis direction and cut-feeded in the Z-axis direction, and the work table on which the work is placed is ground-feeded in the X-direction. The work is integrally attached to a rigid frame via a dicing tape having an adhesive on the surface. The work is placed and processed on the work table while being stuck to the frame in this way. In this dicing device, when processing a work, data relating to the work is input in advance to the controller of the dicing device body and stored in the memory. The data related to the work includes data on the alignment and the thickness of the dicing tape in addition to the product type number, material, external dimensions, thickness, chip size, and the like. The thickness of the work is entered as a standard value determined for each type of work, and the thickness of the dicing tape is entered as the nominal value of the tape maker. When grooving this work, the uncut amount of the work is set, and grooving is performed so that the set amount is left uncut. To perform machining with the set uncut amount, the initial position is the position in the height direction of the rotating blade where the rotating blade and the upper surface of the work table come into contact, and the rotating blade is moved upward by the set uncut amount. Grooving is performed at the position lifted up. For example, when the work is completely cut, the thickness of the dicing tape is 100 μm.
Then, the uncut amount is set to 80 to 90 μm so that the dicing tape is cut to about 10 to 20 μm.

However, in this conventional setting method of the uncut amount, as shown in FIG. 8, for example, the work W placed on the work table 23 via the dicing tape T is
In processing such as bevel cutting that forms a V groove with a rotary blade 21A having a V-shaped tip, when processing is performed with an uncut amount Q, the depth and width of the V groove change due to variations in the thickness of the workpiece W. There was a problem that it ended up. That is,
When the thickness of the work W becomes thicker by δm as shown by the chain double-dashed line in FIG. 8, the V groove does not fit in the street S indicating the processing region and the work W protrudes to the pattern portion P and is processed. It will be.

[0004]

In order to solve such a problem, Japanese Patent Laid-Open No. 7-40335 discloses a camera having an autofocus function to calculate a distance between a blade lower end and a work upper surface. It is described that the groove is processed by lowering the blade by a distance obtained by adding a predetermined cut amount to the calculated distance. However, the accuracy of detecting the top surface of the work by the autofocus function is at most 20 μm.
In order to process a V-groove with a stable width without protruding from the inside of the street S, a workpiece W such as a semiconductor wafer that can be expected only to a certain degree and is becoming narrower due to shrinking design rules, This technique was not enough.

Further, in the conventional dicing apparatus,
When the machining state of the work W is evaluated, the machining part of the upper surface of the work W is imaged with a camera, the groove width and the center position of the groove are calculated from the obtained image, and the size of chipping is measured. It was However, it was not possible to evaluate the depth of the groove and the depth of chipping in the evaluation of the processing state by the image pickup screen of the camera.

The present invention has been made in view of the above circumstances, and is provided with a detector capable of detecting the position of the upper surface of the work in the height direction with high accuracy and also detecting the depth direction of the groove. It is an object of the present invention to provide a dicing device having a function capable of always ensuring a stable depth of cut from the upper surface of a workpiece and further evaluating a processing state including a depth direction.

[0007]

In order to achieve the above object, the invention as set forth in claim 1 is a dicing apparatus for performing a groove processing and a cutting processing of a work placed on a work table by a rotating blade. A laser displacement meter for measuring the upper surface of the work is provided, and the invention according to claim 2 is the dicing apparatus according to claim 1, wherein the work upper surface measured by the laser displacement meter. Is provided with a cutting amount control means for controlling the cutting depth of the rotary blade based on the position in the height direction of the rotating blade, and the invention according to claim 3 is the invention according to claim 2. In the dicing device, a mapping means for creating a map of the work upper surface from the measurement result of the positions in the height direction of the work upper surface by the laser displacement meter is provided. And, wherein the depth of cut control means is characterized by controlling the cutting depth of the rotary blade based on the map. According to the present invention, the position in the height direction of the upper surface of the work is detected with high accuracy by the laser displacement meter, and the cutting depth of the rotary blade is controlled from that position. The width is secured. Further, since a map of the upper surface of the work is created and the depth of cut is controlled based on the map, stable machining dimensions can be obtained over the entire surface of the work.

Further, in the invention described in claims 4 to 5, in the invention described in the preceding paragraph, the shape of the groove processed on the upper surface of the work is measured by the laser displacement meter, or the upper surface of the processed work is measured. Since the feature is that the dimension of chipping generated in the groove is measured, it is possible to evaluate the processing situation including the dimension in the depth direction.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a dicing apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. In each drawing, the same members are given the same numbers or symbols.

First, the structure of the dicing apparatus will be described. FIG. 1 is a perspective view showing the outer appearance of a dicing apparatus according to the present invention. The dicing device 10 includes a load port 60 for transferring a cassette accommodating a plurality of works to and from an external device, a carrying unit 50 having a suction unit 51 for carrying the works to each part of the device, and detecting an upper surface of the works. The laser displacement meter 81, the processing unit 20, the spinner 40 for cleaning and drying the processed work, the controller 100 for controlling the operation of each unit of the apparatus, and the like. The processing unit 20 is provided with two air bearing spindles 22 and 22 of a high frequency motor built-in type, which are arranged so as to face each other and to which a rotary blade 21 is attached.
While being rotated at a high speed of 0000 rpm to 60,000 rpm, index feeding in the Y direction and cutting feed in the Z direction in the figure are performed independently of each other. Further, the work table 23 on which the work is sucked and placed is configured to be ground and fed in the X direction in the drawing by the movement of the X table 30.

FIG. 2 is a front view for explaining the main part of the dicing apparatus 10. The dicing device 10 has an X table 25 which is moved in the X direction by a driving means (not shown), and a θ table 24 which rotates in the θ direction in the drawing is placed on the X table 25. A work table 23 is attached. The work W to be processed is attached to the frame F via a dicing tape T having an adhesive on the surface and adsorbed to the work table 23. At the same time, the frame F is placed on the pedestals 32, 32, ... Attached to the work table 23.
32, ... Rotary actuators 3 provided respectively
It is designed to be clamped by the third clamper 34.
The work W is rotated in the θ direction and is ground and fed in the X direction by such a mechanism. On the other hand, spindle 2
The rotary blade 21 attached to the No. 2 is covered with a flange cover 26 whose front and bottom surfaces are open, and the flange cover 26 is provided with cooling nozzles 27, 27 for supplying cooling water such that the rotary blade 21 is sandwiched in the front and back. It is provided. The rotary blade 21 has a thin disk shape, and an electrodeposition blade in which diamond abrasive grains or CBN abrasive grains are electrodeposited with nickel or a resin blade in which resin is bonded is used. Further, the spindle 22 is subjected to the cutting feed in the Z direction and the index feed in the Y direction (perpendicular to the paper surface) of FIG. A microscope 72 is attached to the spindle 22 via a holder arm 71.
A laser displacement meter 81 is attached to the unit 2 so that the laser beam 81A can be emitted toward the work W. The laser displacement meter 81 is a general length-measuring device using a semiconductor laser or a helium neon laser, and its structure and measurement principle are already known, so description thereof will be omitted. Since the laser displacement meter 81 is thus fixed to the spindle 22 via the microscope 72 and the holder arm 71, the index feed in the Y direction and the cut feed in the Z direction are performed together with the rotary blade 21 and the microscope 72. . Further, the controller 100 that controls the operation of each part of the dicing device is provided with mapping means 82 that receives the displacement data of each part of the upper surface of the work W detected by the laser displacement meter 81 and creates a map of the upper surface of the work W. . This map shows XY of each part of the upper surface of the work W.
The coordinates are associated with the Z coordinates at that position. The controller 100 also has a mapping means 82.
Cutting depth control means for controlling the height of the rotary blade 21 is provided on the basis of the map created by.

Next, the relative positional relationship between the lower end of the rotary blade 21 and the irradiation position of the laser beam 81A of the laser displacement meter 81 will be described. First, the microscope 72 is initially adjusted so that the cross line of the microscope 72 is located on the extension line in the X direction at the lowermost end of the rotary blade 21. Further, the distance in the X direction between the lowermost position of the rotary blade 21 and the cross line position of the microscope 72 is measured in advance and is input to the system data in the controller 100 as a known value. Also, the laser light 8 of the laser displacement meter 81
The irradiation position of 1A and the cross line position of the microscope 72 are
In the relationship as shown in FIG. 3, the offset amounts Δx and Δy in both the X and Y directions at both positions are measured in advance and are also input to the system data in the controller 100. Therefore, the relative positional relationship between the lowermost point of the rotary blade 21 and the cross line position of the microscope 72 is known, and the cross line position of the microscope 72 and the laser beam 81A are known.
Since the relative positional relationship between the irradiation position of the laser beam 81A and the processing point of the rotary blade 21 is also a known value.

Next, the operation of the dicing device thus constructed will be described. First, a cassette containing a plurality of works W attached to the frame F via the dicing tape T is delivered to the load port 60 of the dicing device 10 by the external transport means. Next work W
Are taken out of the cassette one by one by the conveyance means 50 of the dicing device 10 and adsorbed on the work table 23. After that, the work table 23 moves under the microscope 72, and the pattern portion P formed on the upper surface of the work W.
Are imaged by a CCD camera connected to the microscope 72, and are aligned using a known pattern matching method. Then, the position of the upper surface of the work W in the Z direction is measured under the laser displacement meter 81. In this measurement, the laser displacement meter 81 is first positioned at the Z direction initial position, and then the Y direction index feed of the laser displacement meter 81 and the X direction feed of the work W are scanned over the front surface of the upper surface of the work W, and each XY coordinate is measured. Z coordinate value data corresponding to is acquired. The acquired data is the controller 1
It is sent to the mapping means 82 in 00 to create a map of the upper surface of the work W. Since the lower end position coordinates of the rotary blade 21 at the Z-axis initial position are measured and known in advance, the Z coordinates for cutting a predetermined amount from the upper surface position of the work W can be easily obtained by simple calculation. When the map of the work W is created, the work W is sent to the processing unit 20 and processing is started. In machining, the cutting amount control means 83 in the controller 100 controls the Z direction position of the rotary blade 21 according to the map of the upper surface of the work W created by the mapping means 82. One line is processed by grinding feed of the work table 23 in the X direction, and then the rotary blade 21 is index-fed one pitch in the Y direction to move to the next street S.
This line is also processed by the X-direction grinding feed of the work table 23. By repeating this operation, all the streets S of the work W in one direction are processed. When all lines in one direction are processed, θ table 24
The work W is rotated by 90 degrees by the rotation of, and the street S which is orthogonal to the street S is processed. The position control of the rotary blade 21 in the Z direction may be performed on a line-by-line basis on the basis of a representative value (for example, an average value) of the Z coordinates of the line, or it may be controlled constantly depending on the positions in the X and Y directions. You may process it, controlling.

FIG. 4 shows a result of measuring one line in the Y direction on the upper surface of the work W with the laser displacement meter 81. The horizontal axis of the figure represents the Y coordinate (mm), and the left vertical axis represents the workpiece W.
The displacement (μm) in the Z direction on the upper surface is shown. The right vertical axis indicates the Z position correction amount (μ
m) is represented. As shown in FIG. 4, the Y-direction position Y
Z of the rotary blade 21 according to ₁ , Y ₂ , Y ₃ , ... Y _i
The position correction amount _{m 1, m 2, m 3} , by a ... m _i, stable cutting depth is obtained.

FIG. 5 shows a rotary blade 21A having a V-shaped tip.
Control the depth of cut in this way by using
It shows the state of grooving. As shown in FIG. 5, the state represented by the solid line in the figure shows a state in which a V groove is machined in the street S on the upper surface of the work W with a cutting depth R, and the two-dot chain line in the figure indicates that the upper surface of the work W is δm above It shows that the rotary blade 21A is lifted upward by δm when the change is made, and the cut amount R is maintained. Since the rotary blade 21A is controlled so that the cutting depth becomes constant in this way, the groove width is also kept constant and the pattern portion P is not damaged.

FIG. 6 shows two opposing spindles 22.
It shows a state in which the street S of the work W is subjected to a two-stage cut including a bevel cut and a cutting process by using a rotary blade 21A having a V-shaped tip provided on A and 22B and a rotary blade 21B having a thin blade. . FIG. 6A shows a state in which the bevel cut is performed on the street S by the rotary blade 21A, and FIGS. 6B and 6C show the state where the bevel cut by the rotary blade 21A is delayed by three lines. This shows a state where full cutting is being performed by the blade 21B. In this full cut, the cutting depth is controlled so as to cut the dicing tape T by 10 μm to 20 μm. The purpose of this processing is to first obtain a good chip by forming a shallow groove with less chipping by performing a bevel cut with a rotating blade 21A having a fine grain size, and by fully cutting with a rotating blade 21B in the groove. It is in. Since the edge portion of the upper surface of the thus obtained chip is chamfered over the entire circumference, the edge portion will not be chipped in the subsequent step of the dicing step.

The workpiece W, which has been completely processed, is scanned again with a laser beam 81A for a processing groove under the laser displacement meter 81, and its shape and chipping condition are measured and evaluated. FIG. 7 shows an example of evaluation contents. Figure 7
In (a), the laser beam 81A of the laser displacement meter 81 is V
By scanning in the direction that crosses the groove, the groove width, groove depth,
And the angle of V are measured. Also,
The width and depth of the square groove as shown in FIG. 7B, the center position of the groove, and the radius of curvature of the groove bottom corner, and the width of the chipping generated at the groove upper edge portion as shown in FIG. 7C. , And depth are measured. Among these measurements, the measurement in the depth direction in particular cannot be performed by the measurement with the camera image, and the laser displacement meter 81 enables accurate measurement.

After the evaluation of the processed groove, the work W is carried to the spinner 40 by the carrying means 50, where the spin cleaning and the spin drying are performed. The work W, which has been cleaned and dried, is stored in the original cassette by the transporting means 50 again. The above is the flow of processing the work W by the dicing apparatus according to the present invention.

As described above, according to the present invention, the upper surface position of the work W is measured by the laser displacement meter 81 prior to processing, and the rotary blade 21 is controlled by the cutting depth from the upper surface. Even if the thickness of the work W varies, the depth of cut is stable, and the groove width does not change during V-groove processing.

In this embodiment, the laser displacement meter 81
Although it is attached to the alignment microscope 72, the invention is not limited to this, and a dedicated drive means may be provided to move the microscope 72, or the microscope may be fixed without moving.

[0021]

As described above, according to the present invention, the position in the height direction of the upper surface of the work placed on the work table is detected with high accuracy by the laser displacement meter prior to processing, and the rotary blade is detected from that position. Since the cutting depth of is controlled, the depth of the groove is stabilized, and a stable groove width is secured in the case of V-groove processing, for example. Further, since a map of the upper surface of the work is created and the depth of cut is controlled based on the map, stable machining dimensions can be obtained over the entire surface of the work.

Further, since the shape of the groove machined on the upper surface of the work can be measured by the laser displacement meter, or the size of chipping generated in the groove on the upper surface of the machined work can be measured, the dimension in the depth direction can also be measured. It is possible to evaluate the processing status including.

[Brief description of drawings]

FIG. 1 is a perspective view showing the outer appearance of a dicing apparatus according to an embodiment of the present invention.

FIG. 2 is a front view illustrating a main part of the dicing device according to the embodiment of the present invention.

FIG. 3 is a perspective view showing an offset amount between a laser beam irradiation position and a microscope crossline position.

FIG. 4 is a graph showing a measurement result of a work top surface position.

FIG. 5 is a cross-sectional view illustrating control of a cutting amount from the top surface of a work.

FIG. 6 is a cross-sectional view illustrating a two-stage cut of a bevel cut and a full cut with an opposed spindle.

FIG. 7 is a cross-sectional view illustrating measurement of a machining groove.

FIG. 8 is a cross-sectional view illustrating conventional uncut amount control.

[Explanation of symbols]

10 ... Dicing device, 21.21A.21B ... Rotating blade, 22.22A.22B ... Spindle, 23 ... Work table, 72 ... Microscope, 81 ... Laser displacement meter,
81A ... Laser light, 82 ... Mapping means, 83 ... Cut amount control means, 100 ... Controller, F ... Frame, P ... Pattern part, S ... Street, Т ... Dicing tape, W ... Work

Continued front page    (72) Inventor Takayuki Kaneko             9-7 Shimorenjaku, Mitaka City, Tokyo Stocks             Company Tokyo Seimitsu

Claims (5)

[Claims] 1. A dicing device for grooving or cutting a work placed on a work table by a rotary blade, wherein a laser displacement meter for measuring the upper surface of the work is provided. . 2. A cutting amount control means for controlling a cutting depth of the rotary blade based on a height direction position of the work upper surface measured by the laser displacement meter. Item 1. The dicing device according to item 1. 3. A mapping means for creating a map of the work top surface from the measurement results of the positions in the height direction of a plurality of points on the work top surface by the laser displacement meter, wherein the cutting amount control means is based on the map. The dicing apparatus according to claim 2, wherein the cutting depth of the rotary blade is controlled. 4. The dicing apparatus according to claim 1, wherein the shape of the groove processed on the upper surface of the work is measured by the laser displacement meter. 5. The laser displacement meter measures the dimension of chipping generated in a groove on the upper surface of the work piece processed, according to any one of claims 1, 2, 3 and 4. The dicing device described.