JP2013062430A - Method for dividing laminated workpiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for dividing a laminated workpiece, capable of accurately cutting even a workpiece in which disk-shaped objects having different diameters are laminated, and preventing damage to a cutting blade and the workpiece due to dispersion of mill ends.SOLUTION: A method for dividing a laminated workpiece in which first and second disk-shaped objects having different diameters are laminated into individual chips by using a cutting blade, includes: a holding step of holding the laminated workpiece by a chuck table; an outer peripheral edge cutting step of allowing a first cutting blade to cut into an outer peripheral edge of the laminated workpiece while relatively moving the first cutting blade and the chuck table to cut the outer peripheral edge of the laminated workpiece by the first cutting blade to make the diameters of the first and second disk-shaped objects identical; a first disk-shaped object cutting step of cutting the first disk-shaped object along scheduled cutting lines; and a second disk-shaped object cutting step of cutting the second disk-shaped object along the scheduled cutting lines to divide the laminated workpiece into individual chips.

Description

  The present invention relates to a method for dividing a laminated workpiece in which a laminated workpiece in which two disk-like objects having different diameters are laminated is divided.

  For cutting workpieces such as semiconductor wafers, ceramic substrates, resin substrates, and glass substrates, a cutting device called a dicer provided with a cutting unit having a cutting blade is widely used.

  The cutting blade has an annular cutting blade with a thickness of about 15 to 300 μm, which is made of superabrasive grains such as diamond and CBN (Cubic Boron Nitride), which are hardened with a metal or a resin. The workpiece is divided by cutting into the workpiece and cutting and removing a part of the workpiece.

  In recent years, it has been attempted to cut a laminated workpiece in which two workpieces are laminated with a cutting device. Examples of the laminated workpiece include a laminated workpiece in which a glass cap wafer is laminated on a MEMS (Micro Electro Mechanical Systems) wafer, a WL-CSP wafer in which a device wafer surface is resin-molded, and an imaging device such as a CMOS or CCD. Examples include a laminated workpiece in which a protective wafer is laminated on a lens wafer to be a lens, and a sensor optical component (Sensing Optics).

  When such a laminated workpiece is cut with a cutting blade, the laminated workpiece is generally thick. Therefore, by cutting from the front and back sides of the laminated workpiece, the cutting edge of the cutting blade can be extended. The amount is reduced, the cutting blade is prevented from being bent during cutting, and high-accuracy cutting is possible. Further, the cutting load is reduced, and the occurrence of chipping can be suppressed.

  Japanese Patent Application Laid-Open No. 2003-31734 discloses a method of suppressing chipping generated by cutting by cutting with a cutting blade from both the front and back sides of the workpiece and dividing the workpiece.

JP 2003-31734 A

  However, in the case of a laminated workpiece in which the first and second disk-shaped objects having different diameters are stacked, cutting is performed with a cutting blade from the first disk-shaped object side and from the second disk-shaped object side, respectively. Then, since the outer peripheral part of the disk-shaped object with a large diameter is not bonded to the disk-shaped object with a small diameter, the outer peripheral part is scattered. There is a possibility that the scattered end material collides with the cutting blade and breaks the cutting blade, or collides with the upper surface of the laminated workpiece and damages the upper surface of the laminated workpiece.

  The present invention has been made in view of the above points, and the object of the present invention is to provide machining accuracy and machining quality even in a laminated workpiece in which first and second disk-like objects having different diameters are laminated. It is an object of the present invention to provide a method for dividing a laminated workpiece capable of cutting well and preventing damage to a cutting blade and a laminated workpiece caused by scattering of end materials.

  According to the present invention, a laminated workpiece obtained by laminating a second disk-shaped object having a second diameter different from the first value on a first disk-shaped object having a first diameter is cut with a cutting blade. A method of dividing a multilayer workpiece to be divided into individual chips, comprising: a holding step for holding the multilayer workpiece on a chuck table; and an outer periphery of the multilayer workpiece held on the chuck table. While cutting one cutting blade, the first cutting blade and the chuck table are moved relative to each other to cut the outer peripheral edge of the laminated workpiece with the first cutting blade. After performing the outer periphery cutting step for making the diameter of the second disk-shaped object the same, and the outer periphery cutting step, a second cutting blade is cut into the first disk-shaped object side of the laminated workpiece First, the first disk-shaped object is cut along the planned cutting line. After carrying out the plate-shaped object cutting step and the first disk-shaped object cutting step, a third cutting blade is cut into the second disk-shaped object side of the laminated workpiece, and the second disk-shaped object is cut. A method of dividing a laminated workpiece, comprising: a second disk-like object cutting step for dividing the laminated workpiece into individual chips by cutting the workpiece along a planned cutting line. Provided.

  According to the present invention, first, the outer peripheral edge of the laminated workpiece is cut, so that the diameters of the first disk-shaped object and the second disk-shaped object are the same. After that, the laminated workpiece is cut with a cutting blade from the first disc-like object side and the second disc-like object side, respectively, so that it can be cut with good machining accuracy and machining quality, and the end material is scattered. Can prevent damage to the cutting blade and workpiece.

It is a perspective view of the lamination | stacking workpiece supported by the annular frame via the adhesive tape. It is a partial cross section side view which shows a holding | maintenance step. It is a partial cross section side view which shows an outer periphery cutting step. It is a partial cross section side view which shows a ring-shaped end material removal step. It is a partial cross section side view which shows a 1st disk shaped object cutting step. It is a partial cross section side view which shows a 2nd disk shaped object cutting step.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, a perspective view of a laminated workpiece 11 supported by an annular frame F via a first adhesive tape T1 is shown. The laminated workpiece 11 according to the present embodiment is constituted by a laminated workpiece in which a glass cap wafer 13 is laminated on a MEMS wafer 15, for example.

  The MEMS wafer 15 is configured such that a MEMS device 19 is formed in each region defined by a plurality of scheduled cutting lines 17 formed in a lattice shape. A glass cap wafer 13 is bonded on the surface of the MEMS wafer 15. The back surface of the multilayer workpiece 11, that is, the MEMS wafer 15 side is attached to the first adhesive tape T 1, and the outer peripheral portion of the first adhesive tape T 1 is attached to the annular frame F.

  The laminated workpiece to which the dividing method of the present invention is applied is not limited to the laminated workpiece 11 in which the glass cap wafer 13 is laminated on the MEMS wafer 15. For example, the laminated workpiece is resin-molded on the surface of the device wafer. In addition, the present invention includes a laminated workpiece in which a protective wafer is laminated on a lens wafer to be a lens of an imaging device such as a WL-CSP wafer, a CMOS or a CCD, a sensor optical component (Sensing Optics) laminated workpiece, and the like.

  In the method for dividing a multilayer workpiece according to the present embodiment, first, as shown in FIG. 2, a holding step of sucking and holding the multilayer workpiece 11 by the chuck table 10 of the cutting apparatus is performed. In this holding step, the annular frame F is further clamped and fixed by the clamp 12.

  Next, as shown in FIG. 3, the chuck table 10 is rotated while the first cutting blade 16 of the cutting unit 14 rotating at a high speed is cut into the outer peripheral edge of the multilayer workpiece 11 held by the chuck table 10. The outer peripheral edge of the laminated workpiece 11 is cut by the first cutting blade 16, and the outer peripheral edge cutting step is performed so that the diameter of the MEMS wafer 15 is the same as the diameter of the glass cap wafer 13. When this outer peripheral cutting step is performed, depending on the size of the MEMS wafer 15, the ring-shaped end material 21 remains as shown in FIG. 4, but this ring-shaped end material 21 is peeled off from the first adhesive tape T1 and removed. Is preferred.

  In this outer peripheral edge cutting step, the outer peripheral edge of the multilayer workpiece 11 is cut a plurality of times while changing the cutting depth instead of one time cutting, so that the diameter of the MEMS wafer 15 is the same as the diameter of the glass cap wafer 13. May be.

  After performing the outer periphery cutting step, as shown in FIG. 5, the laminated workpiece 11 is sucked and held by the chuck table 20 of a cutting device different from that used in the outer periphery cutting step, and the annular frame F is clamped by the clamp 22. Clamp and fix.

  After performing the alignment for aligning the second cutting blade 24 with the planned cutting line 17 to be cut, the second cutting blade 24 rotating at a high speed in the direction of the arrow A is used as a glass cap wafer (first disc shape) of the laminated workpiece 11. A glass cap wafer (first disc-like material) cutting step for cutting the glass cap wafer 13 along the planned cutting line 17 by cutting the workpiece into the object 13 and feeding the chuck table 20 in the direction of the arrow X1. carry out.

  The cutting blades 24 are indexed and fed by the pitch of the planned cutting line 17 to cut the glass cap wafer 13 along all the planned cutting lines 17 extending in the first direction. Next, after rotating the chuck table 20 by 90 degrees, the glass cap wafer 13 is cut along all the planned cutting lines 17 extending in the second direction orthogonal to the first direction.

  When the first disk-shaped object cutting step is completed, the MEMS wafer (second disk-shaped object) side of the laminated workpiece 11 is adhered to the second adhesive tape T2, and the outer peripheral portion of the second adhesive tape T2 is annular. Affixing step for attaching the first adhesive tape T1 to the frame F and peeling the first adhesive tape T1 from the laminated workpiece 11 and the annular frame F is performed.

  After performing the replacement step, as shown in FIG. 6, the laminated workpiece 11 is sucked and held by the chuck table 20 of the cutting device, and the MEMS workpiece (second disc-like object) 15 side of the laminated workpiece 11. To expose. Then, the annular frame F is clamped and fixed by the clamp 22.

  Then, alignment is performed in which the MEMS wafer 15 is imaged from the back side with an infrared camera to detect the planned cutting line 17. After alignment, the second cutting blade 24 is rotated in the direction of arrow A at a high speed, and cut into the MEMS wafer (second disk-shaped object) side of the laminated workpiece 11, and the chuck table 20 is processed and fed in the direction of arrow X1. Then, a MEMS wafer (second disk-like) cutting step for cutting the MEMS wafer 15 along the planned cutting line 17 is performed.

  The second cutting blade 24 is indexed and fed by the pitch of the planned cutting line 17, and the MEMS wafer 15 is cut along all the planned cutting lines 17 extending in the first direction. Next, after rotating the chuck table 20 by 90 degrees, the laminated wafer 11 is cut by cutting the MEMS wafer 15 along all the planned cutting lines 17 extending in the second direction orthogonal to the first direction. Is divided into individual chips.

  In the above-described embodiment, the glass cap wafer 13 is fully cut in the first disc-like material cutting step, and the MEMS wafer 15 is fully cut in the second disc-like material cutting step. The method is not limited to this form.

  For example, in the first disk-shaped object cutting step, the first disk-shaped object (glass cap wafer) 13 is half-cut to form an uncut portion, and then the second disk-shaped object cutting step is performed. Thus, the uncut portion of the first disk-shaped object (glass cap wafer) may be cut together with the second disk-shaped object (MEMS wafer) 15.

  In the embodiment described above, the first disc-shaped object cutting step for cutting the glass cap wafer 13 and the second disc-shaped object cutting step for cutting the MEMS wafer 15 are performed by the same cutting blade 24. The second disc-shaped object cutting step for cutting the MEMS wafer 15 may be performed by a third cutting blade different from the second cutting blade 24.

  The first, second, and third cutting blades may be the same cutting blade, different cutting blades, or any one of them may be the same cutting blade. Furthermore, the holding step, the outer peripheral edge cutting step, the first disk-like object cutting step, and the second disk-like object cutting step may be performed by the same cutting device, or may be performed by different cutting devices. .

10, 20 Chuck table 11 Laminated workpiece 13 Glass cap wafer (first disc-shaped object)
15 MEMS wafer (second disk)
16 First cutting blade 17 Planned cutting line 19 Device 24 Second cutting blade T1 First adhesive tape T2 Second adhesive tape F Annular frame

Claims (1)

Each of the chips is obtained by cutting a laminated workpiece in which a second disk-shaped object having a second diameter different from the first diameter is stacked on a first disk-shaped object having a first diameter with a cutting blade. A method of dividing a laminated workpiece to be divided into
A holding step for holding the laminated workpiece on the chuck table;
The first cutting blade is cut into the outer peripheral edge of the multilayer workpiece held by the chuck table, and the first cutting blade and the chuck table are moved relative to each other to move the outer peripheral edge of the multilayer workpiece. An outer peripheral cutting step in which cutting is performed with one cutting blade so that the diameters of the first disk and the second disk are the same;
After performing the outer peripheral cutting step, a second cutting blade is cut into the first disk-like object side of the laminated workpiece, and the first disk-like object is cut along a planned cutting line. 1 disc cutting step,
After performing the first disk-like object cutting step, a third cutting blade is cut into the second disk-like object side of the laminated workpiece, and the second disk-like object is cut along a planned cutting line. A second disk-shaped object cutting step for dividing the laminated work piece into individual chips by cutting with
A method for dividing a laminated workpiece, comprising:

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