JP3722271B2 - Wafer cutting apparatus and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wafer cutting apparatus and method for cutting a semiconductor wafer into dice by rotating two blades mounted on two spindles.
[0002]
[Prior art]
A dicing apparatus that cuts a semiconductor wafer into dice is a device that cuts a semiconductor wafer into dice along a street by rotating a blade mounted on a spindle at high speed, and divides the wafer into chips.
[0003]
As a conventional dicing apparatus, a dual-type dicing apparatus having two spindles is known (Japanese Patent Laid-Open No. 8-25209, Japanese Utility Model Laid-Open No. 59-156753, etc.). According to this dicing apparatus, since two streets of the semiconductor wafer can be cut simultaneously with two blades, there is an advantage that the cutting time of the semiconductor wafer can be shortened.
[0004]
[Problems to be solved by the invention]
However, the conventional dual-type dicing apparatus can reduce the cutting time to about half by increasing the spindle from one to two. There was a drawback that high quality and high throughput could not be expected.
[0005]
By the way, in the dicing apparatus, the street is fully cut with one blade and the street is cut in two steps using two different blades (half cut with the first blade and then with the second blade). There is a method of full cut). In the former full-cut method, the rotation direction of the spindle (the rotation direction of the spindle at the cutting point of the blade) and the cutting / feeding direction of the wafer are set to coincide with each other in order to suppress chipping generated on the surface of the wafer ( Hereinafter referred to as “down cut”). In the latter two-stage cutting method, the same rotational direction as the full-cut method is set to suppress chipping on the surface, but in the case of full-cutting with the second blade, the wafer In order to suppress chipping generated on the back surface of the wafer, the rotation direction of the spindle and the cutting and feeding direction of the wafer are set to be opposite directions (hereinafter referred to as “upcut”).
[0006]
Furthermore, even in such a full cut by down-cut or a two-stage cut by down-cut and up-cut, from the viewpoint of improving throughput, the wafer is cut when moving in the forward direction and the blade is released upward when moving in the backward direction. Without cutting, the wafer is moved back to the cutting start position at high speed. In short, when trying to perform high-quality cutting in both directions, it is necessary to process with one blade for each reciprocation or to reverse the spindle rotating at high speed, and in any case, the throughput decreases.
[0007]
On the other hand, in the dicing machine, cutting is performed while supplying cutting fluid to the cutting point of the blade. However, supply of this cutting fluid also requires appropriate and reliable supply from the viewpoint of cutting the semiconductor wafer with high accuracy. Has been.
[0008]
However, in the case where only two spindles are arranged as in the conventional dual-type dicing apparatus, depending on the mutual position and rotation direction of the spindles, the drainage of the cutting fluid supplied to one blade may be the other. The cutting fluid supply of each blade is adversely affected, or the cutting fluid drainage supplied to the cutting points of each blade is mixed and scattered, so the cutting fluid is interrupted by the scattered fluid and cuts the cutting fluid. There was a drawback that it could not be reliably supplied to the point. Further, when the drainage liquid is scattered, the cutting powder mixed in the drainage liquid enters the cutting point to cause chipping, or the cutting powder adheres to the chip.
[0009]
The present invention has been made in view of such circumstances, and is a wafer cutting apparatus having two spindles, which can efficiently cut a wafer and achieve high quality and high throughput. And an object thereof.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a wafer cutting apparatus for cutting the wafer by two blades mounted on the two spindles by relatively moving the two spindles and the wafer. The two spindles are arranged opposite to each other in a straight line and rotated in opposite directions when viewed from the blade side (clockwise and counterclockwise when viewed from the blade side), respectively, and the two blades move the wafer. It is characterized by cutting at the same time .
In order to achieve the above object, the present invention provides a wafer cutting method in which the two spindles and the wafer are relatively moved to cut the wafer with two blades attached to the two spindles. The two spindles are arranged opposite to each other in a straight line and rotated in opposite directions as viewed from the blade side (clockwise and counterclockwise as viewed from the blade side), respectively, and the wafer is simultaneously moved by the two blades. It is characterized by cutting.
[0011]
In a wafer cutting apparatus having two spindles and cutting the wafer by two blades mounted on the two spindles by relatively moving the two spindles and the wafer, the 2 this spindle is that is configured such that each rotation direction is switched.
[0012]
In the wafer cutting method having two spindles, the wafer is cut by two blades mounted on the two spindles by relatively moving the two spindles and the wafer. this spindle is configured such that each rotation direction is switched, the two spindles, cut the wafer is rotated in the opposite directions.
[0013]
In the wafer cutting method having two spindles, the wafer is cut by two blades mounted on the two spindles by relatively moving the two spindles and the wafer. this spindle is configured such that each rotation direction is switched, the two spindles, cut the wafer is rotated in the same direction.
[0014]
According to the first and second aspects of the present invention, the two spindles arranged opposite to each other in a straight line are rotated in opposite directions, and the two spindles and the wafer are moved relative to each other. Cut the wafer down or up with the blade. In this way, when the two spindles arranged opposite to each other in a straight line are rotated in opposite directions, the cutting fluid discharged to the cutting point of each blade is discharged in the same direction. A drainage splash prevention cover or the like may be provided only in one side direction, and the structure is simple. Further, in the present invention, when cutting in the same cut mode (down cut or up cut), the throughput is higher than that in which two spindles are rotated in the same direction (FIG. 5).
[0015]
On the other hand, when two spindles are arranged in parallel, when the two blades are arranged on the same cutting line, the respective cutting fluids are discharged in the opposite direction without mixing with each other. Does not adversely affect. Therefore, it is possible to reliably supply a switching Kezueki the cutting point (FIG. 10). Also, when two spindles are shifted back and forth and arranged in parallel, the first blade can be down-cut and the second dissimilar blade can be up-cut at the same time, thus achieving high quality and high throughput. (FIG. 11).
[0016]
Has two spindles, a device configured switched the direction of rotation of the two spindles, there is also further comprises a dicing apparatus with a programmable set this switching, two spindles In the same manner as in the first aspect of the invention, the cutting fluid drainage processing structure can be simplified and high throughput can be achieved when cutting in the same cut mode. be able to. Further, when the two spindles are rotated in the same direction, the first-stage downcut and the second-stage upcut can be performed simultaneously, and the two-stage cut with different blades can be performed with high quality and high throughput. On the other hand , when the two spindles are arranged in parallel and rotate reversely, the cutting fluids do not interfere with each other when the two blades are arranged on one straight line. In addition, by shifting the two blades forward and backward in the spindle axis direction, the first blade can be down-cut and the second different blade can be up-cut at the same time. High throughput can be achieved. Further, in the case of rotating in the same direction in the parallel arrangement, the structure for preventing the drainage splash can be simplified and high throughput can be achieved in the same cut mode cutting (FIG. 12).
[0017]
When the two spindles are rotated in opposite directions and the wafer is cut, when the two spindles are arranged to face each other, the drainage treatment structure can be simplified and the same direction when cutting in the same cut mode. High throughput can be achieved compared to rotation (FIG. 5).
[0018]
Further, when two spindles are arranged in parallel, the cutting fluid can be prevented from interfering with each other, so that the cutting fluid can be reliably supplied to the cutting point. In addition, by shifting the two blades forward and backward, a two-stage cut can be performed with high quality and high throughput (FIG. 11).
[0019]
When cutting the wafer by rotating the two spindles in the same direction, if the two spindles are placed facing each other, the first blade is used for downcutting, and the second different blade is used for upcutting. Since it can be performed simultaneously, high quality and high throughput can be achieved (FIG. 7). In addition, when two spindles are arranged in parallel, when cutting in the same cut mode (down cut or up cut), the throughput is increased and the drainage treatment structure can be simplified (FIG. 12).
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a wafer cutting apparatus and method according to the present invention will be described in detail with reference to the accompanying drawings.
[0021]
FIG. 1 is a perspective view of a semiconductor wafer dicing apparatus 10 to which the present invention is applied, and FIG. 2 is a plan view thereof. As shown in FIG. 1, the dicing apparatus 10 mainly includes a cutting unit 12, a cleaning unit 14, a cassette storage unit 16, an elevator unit 18, a transport device 20, and the like.
[0022]
The cutting process of the wafer W by the dicing apparatus 10 will be described. First, the cassette storage unit 16 stores a plurality of wafers attached to the frame via an adhesive sheet. The unprocessed wafers W are sequentially pulled out by the elevator unit 18, and the pulled wafers W are set at a position P4 shown in FIG. Next, the wafer W is placed on the cutting table (position P2) (not shown) of the cutting unit 12 by the transfer device 20 via the preload stage at the position P1. Here, the wafer W is sucked and held on the cutting table. The wafer W held by suction is image-recognized by the alignment imaging devices 22 and 24, and the alignment is performed based on the image recognition.
[0023]
The aligned wafer W has a Y-axis direction movement indicated by arrows A and B of the cutting unit 12 and a Z-axis direction movement perpendicular to the paper surface (not shown) and X indicated by arrows C and D of the cutting table shown in FIG. It is cut into chips by a combined operation with axial movement. First, the cutting table moves in the X-axis direction, and the two streets are simultaneously cut by the two blades 30 and 32 of the cutting blade units 26 and 28. When the first two streets are cut, the cutting blade units 26 and 28 are moved in the Y-axis direction by the street pitch, and the cutting table is moved again in the X-axis direction to move to the next two streets. The street is cut by the two blades 30 and 32. When a street is cut in two steps, the first blade performs only a half cut and the next blade performs a full cut and performs a two-step cut. When such a cutting operation is repeated and cutting of all streets in one direction (X direction) is completed, the cutting table is rotated by 90 ° in the other direction orthogonal to the cut streets (in FIG. 2). The street in the Y direction is sequentially cut by the two blades 30 and 32. Thereby, the wafer W is cut into dice and divided into chips.
[0024]
The wafer W that has been cut is returned to the position P2 by the movement of the cutting table, and then transferred to the spinner table of the cleaning unit 14 at the position P3 by the transfer device 20. Here, the wafer W is cleaned by cleaning water and then dried by air blow. The dried wafer W is transferred to the position P4 by the transfer device 20 and stored in the cassette storage unit 16 by the elevator unit 18. The above is the cutting process of one wafer W by the dicing apparatus 10.
[0025]
As shown in FIG. 3, the cutting blade units 26 and 28 of the cutting unit 12 have spindles 34 and 36 in which high-frequency motors are built, and blades 30 and 32 attached to the tips of the spindles 34 and 36. The two spindles 34 and 36 of these cutting blade units 26 and 28 are disposed so as to face each other, and are arranged at positions where their respective axis centers coincide with the Y-axis direction. The cutting blade units 26 and 28 are connected to a spindle moving mechanism 46 through holders 42 and 44, and are independently moved in the Y-axis direction by the spindle moving mechanism 46. The spindle moving mechanism 46 uses a linear motor, and its detailed configuration is well known, and is omitted here.
[0026]
FIG. 4 is a detailed view of the distal end portion of the cutting blade unit 26. Since the cutting blade unit 28 has the same structure as the cutting blade unit 26, the description of the cutting blade unit 28 is omitted. The blade 30 of the cutting blade unit 26 is covered with a cover called a flange cover 48, and a cooling water supply tube 50 and a cutting water supply tube 52 are connected to the flange cover 48. The cooling water supply tube 50 is connected to a pair of L-shaped nozzles 54, 54 provided at the lower part of the flange cover 48. The pair of nozzles 54, 54 are arranged side by side so as to sandwich the blade 30, and an injection port (not shown) of the nozzles 54, 54 is formed toward the cutting portion of the wafer W by the blade 30. Therefore, the cooling liquid 56 supplied from the cooling water supply tube 50 is supplied to the cutting portion from the injection port of the nozzle 54. Further, the cutting fluid 58 supplied from the cutting water supply tube 52 is supplied to and attached to the cutting edge of the blade 30 from the nozzle 60 provided inside the flange cover 48, and the wafer W by the blade 30 in the attached state. Supplied to the cutting point.
[0027]
Next, a method of cutting the wafer W by the cutting blade units 26 and 28 configured as described above will be described with reference to FIGS.
[0028]
FIG. 5 shows an example in which the wafer W is moved in the C direction while the two spindles 34 and 36 arranged opposite to each other (arranged in a straight line) are rotated in opposite directions to down-cut the wafer W. Has been. That is, the spindle 34 is rotated in the clockwise direction as viewed from the direction of arrow A in FIG. 5 to suppress chipping, and the spindle 36 is also viewed from the direction of arrow B in FIG. Is rotated counterclockwise.
[0029]
Under such conditions, when the wafer W is moved in the direction C, the two streets are cut at the same time by the two blades 30 and 32, and the cut lines L1 and L2 are formed on the two streets. Will be formed.
[0030]
FIG. 6 is a diagram showing the positional relationship between the wafer W and the cutting blade units 26 and 28 when two streets are fully cut. After that, when the next two streets are fully cut, the blades 30 and 32 are moved in the Z direction and then moved in the Y direction by one pitch of each street, and the wafer is moved at a high speed in the D direction. To position at the cutting start position. Thereafter, when the blades 30 and 32 are returned to the Z direction and the wafer W is moved in the C direction at a low speed, the next two streets are fully cut simultaneously by the two blades 30 and 32.
[0031]
As described above, according to the cutting blade units 26 and 28 of the present embodiment, the two spindles 34 and 36 arranged opposite to each other are rotated in opposite directions, so that the cutting points of the blades 30 and 32 are set at the cutting points. Since the supplied cutting fluids (drainage fluids) 58 and 58 are discharged in the same direction (rotation direction side of the blades 30 and 32) as shown by the arrows in FIG. 5, drainage treatment such as a drainage splash prevention cover The structure can be simplified. Further, in this embodiment, when cutting in the same cut mode (down cut or up cut), the throughput is higher than that in which two spindles are rotated in the same direction.
[0032]
FIG. 7 shows an example of a pair of cutting blade units in which two spindles 34 and 36 are opposed to each other and the two spindles 34 and 36 are rotated in the same direction. In this example, as shown in FIGS. 8 and 9, the wafer W is down-cut with the first blade 30 (FIG. 8A), and a half-cut cut line La is formed on the wafer W. Then, the inside of the cut line La is up-cut by the different type blades 32 (FIG. 8B) to form a full-cut cut line Lb on the wafer W. According to this cutting method, the first plurality of cuts are performed only by the blade 30, and then the cut line La cut by the blade 30 is fully cut by the blade 32. Since the full cut at this time can be performed simultaneously with the half cut by the blade 30, high quality and high throughput can be achieved.
[0033]
FIG. 10 shows an example of a pair of cutting blade units in which two spindles 34 and 36 are arranged in parallel. Also in this cutting blade unit, when the spindles 34 and 36 are rotated in the opposite directions, the respective cutting fluids 58 and 58 are mixed and do not interfere with each other and are discharged in the opposite directions as indicated by the arrows in FIG. Therefore, it does not adversely affect the other. Therefore, the cutting fluids 58 and 58 can be reliably supplied to the cutting point even in a cutting section in which the two spindles 34 and 36 are arranged in parallel. Therefore, no cutting defects such as seizure occur in the wafer W, and the wafer W can be accurately cut without any chips being mixed into the cutting portion.
[0034]
FIG. 11 shows an example of a pair of cutting blade units in which two spindles 38 and 40 are arranged in parallel and shifted by a predetermined amount in the Y direction. Also in this cutting blade unit, when the spindles 34 and 36 are rotated in the opposite directions, the cutting fluids 58 and 58 are discharged in the opposite directions as indicated by the arrows in FIG. 11 without mixing. Does not scatter. Therefore, the wafer W can be cut with high accuracy.
[0035]
Also, in the cutting blade unit of FIG. 11, the wafer W is down-cut by the first blade 32, a half-cut line is formed on the wafer W, and the half-cut line is up-cut by the second different blade 30. Thus, a full-cut cut line can be formed on the wafer W. According to this cutting method, the first plurality of cuts are performed only by the blade 32, and then the half cut line cut by the blade 32 is fully cut by the blade 30. Since the full cut at this time can be performed simultaneously with the half cut by the blade 32, high quality and high throughput can be achieved. When the blades 30 and 32 are reversed with respect to the rotation direction of FIG. 11, the two spindles 34 and 36 are arranged with a predetermined amount shifted in the Y direction, so that the respective cutting fluids 58 and 58 are mixed. It is discharged without fitting. Therefore, in this case as well, the wafer W can be cut with high accuracy. In this case, half cutting is performed by the blade 30 and full cutting is performed by the blade 32.
[0036]
FIG. 12 shows an example of a pair of cutting blade units in which two spindles 38 and 40 are arranged in parallel and shifted by a predetermined amount in the Y direction, and the two spindles 38 and 40 are rotated in the same direction. It is shown. Also in this cutting blade unit, since the two spindles 38, 40 are arranged with a predetermined amount shifted in the Y direction, the respective cutting fluids 58, 58 are discharged without being mixed. Therefore, this cutting blade unit can similarly cut the wafer W with high accuracy. Furthermore, since the cutting fluid supplied to the blades 30 and 32 is discharged in the same direction, the structure of the anti-scattering cover and the like can be simplified. Moreover, when this cutting blade unit cuts in the same cut mode (down cut or up cut), the throughput becomes high.
[0037]
【The invention's effect】
As described above, according to the wafer cutting apparatus and method therefor according to the present invention, in the dicing apparatus having two spindles, the two spindles are arranged in a straight line or in parallel. Since the best rotation direction of the book spindle is defined, the structure of the apparatus can be simplified, the wafer can be cut efficiently, and high quality and high throughput can be achieved.
[Brief description of the drawings]
1 is an overall perspective view of a dicing apparatus to which the present invention is applied. FIG. 2 is a plan view of the dicing apparatus shown in FIG. 1. FIG. 3 is a plan view showing a structure of a cutting portion of the dicing apparatus shown in FIG. 4 is a perspective view showing a structure of a cutting blade unit of the cutting section shown in FIG. 3. FIG. 5 is an explanatory view showing a wafer cutting method by the cutting section shown in FIG. 3. FIG. FIG. 7 is a plan view of a cutting section in which two streets are cut by two opposing spindles. FIG. 8 is a plan view of the cutting section shown in FIG. FIG. 9 is an enlarged cross-sectional view of a semiconductor wafer cut by a two-stage cutting method. FIG. 10 is a plan view showing a structure of a cutting portion in which two spindles are arranged in parallel. Two spindles are arranged in parallel and shifted in the Y direction FIG. 12 is a plan view showing the structure of a cutting section in which two spindles are rotated in the opposite directions. FIG. 12 shows two spindles arranged in parallel and shifted in the Y direction. Plan view showing the structure of the cutting section rotated in the same direction 【Explanation of symbols】
W ... Semiconductor wafer, 10 ... Dicing machine, 12 ... Cutting unit, 26, 28 ... Cutting blade unit, 30, 32 ... Blade, 34, 36 ... Motor, 38, 40 ... Spindle, 46 ... Spindle moving mechanism, 56 ... Cooling Fluid, 58 ... Cutting fluid

Claims (2)

In a wafer cutting apparatus for cutting the wafer by two blades mounted on the two spindles by relatively moving the two spindles and the wafer,
The two spindles are opposed to each other on a straight line and are rotated in opposite directions when viewed from the blade side, respectively, so that the wafer is simultaneously cut by the two blades . In a wafer cutting method of cutting the wafer by two blades attached to the two spindles by relatively moving the two spindles and the wafer,
A wafer cutting method characterized in that the two spindles are arranged opposite to each other on a straight line, are rotated in opposite directions as viewed from the blade side, and the wafer is simultaneously cut by the two blades.

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